├── 8.数塔问题
    ├── readme.md
    └── shuta.c
├── 6.最优二叉检索树
    └── OBST.cpp
├── 5.最大子段和问题
    ├── readme.txt
    ├── maxInterval_DC.cpp
    └── maxInterval_DP.c
├── 4.简单的社交关系映射
    ├── readme.txt
    └── friend.cpp
├── README.md
├── 7.最长子序列
    ├── LIS.c
    └── LCS.c
├── 2.找K大的数
    └── find_k.cpp
├── 3.字典排序
    └── dicsort.cpp
├── 1.KMP
    └── KMP.cpp
└── .gitignore


/8.数塔问题/readme.md:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/dskyu/Algorithm/HEAD/8.数塔问题/readme.md


--------------------------------------------------------------------------------
/6.最优二叉检索树/OBST.cpp:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/dskyu/Algorithm/HEAD/6.最优二叉检索树/OBST.cpp


--------------------------------------------------------------------------------
/5.最大子段和问题/readme.txt:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/dskyu/Algorithm/HEAD/5.最大子段和问题/readme.txt


--------------------------------------------------------------------------------
/4.简单的社交关系映射/readme.txt:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/dskyu/Algorithm/HEAD/4.简单的社交关系映射/readme.txt


--------------------------------------------------------------------------------
/5.最大子段和问题/maxInterval_DC.cpp:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/dskyu/Algorithm/HEAD/5.最大子段和问题/maxInterval_DC.cpp


--------------------------------------------------------------------------------
/README.md:
--------------------------------------------------------------------------------
 1 | Algorithm
 2 | =========
 3 | 
 4 | 算法练习仓库
 5 | 
 6 | 索引  
 7 | 1.KMP<br/>
 8 | 2.找K大的数<br/>
 9 | 3.字典排序<br/>
10 | 4.简单的社交关系映射<br/>
11 | 5.最大子段和问题<br/>
12 | 6.最优二叉检索树<br/>
13 | 7.最长子序列 LCS LIS<br/>
14 | 8.数塔问题<br/>


--------------------------------------------------------------------------------
/5.最大子段和问题/maxInterval_DP.c:
--------------------------------------------------------------------------------
 1 | #include <stdio.h>
 2 | #include <stdlib.h>
 3 | 
 4 | int maxInterval(int *arr, int left, int right)
 5 | {
 6 | 	int i,sum = 0;
 7 | 	int tmp = 0;
 8 | 	for(i=left; i<right; ++i)
 9 | 	{
10 | 		if(tmp > 0) {tmp += arr[i];}
11 | 		else        {tmp  = arr[i];}
12 | 		if(tmp >sum){sum  = tmp;}
13 | 	}
14 | 	return sum;
15 |                     
16 | }
17 | 
18 | int main()
19 | {
20 |     int a[]={-2, 11, -4, 13, -5, -2};
21 |     printf("%d",maxInterval(a,0,5));
22 |     system("pause");
23 |     return 0;
24 | }
25 | 


--------------------------------------------------------------------------------
/7.最长子序列/LIS.c:
--------------------------------------------------------------------------------
 1 | #include <stdio.h>
 2 | #include <stdlib.h>
 3 | 
 4 | int LIS(int a[],int la)
 5 | {
 6 |     int max,i,j;
 7 |     int s[100]={0};
 8 |     
 9 |     s[0]=1;
10 |     for (i=1;i<la;i++)
11 |     {
12 |         max=0;
13 |         for (j=i;j<i;j++) 
14 |         {    
15 |            if (a[j]<a[i] && max<s[j]) max=s[j];
16 |            s[i]=max+1;  
17 |         }
18 |     }   
19 |     max=0;
20 |     for (i=0;i<la;i++)
21 |         if(max<s[i]) max=s[i];
22 |     return max;
23 | }
24 | 
25 | int main()
26 | {
27 |     int a[]={1,2,3,6,5,7,4,8,6};
28 |     printf ("%d",LIS(a,9));
29 |     system("pause");
30 |     return 0;   
31 | }
32 | 


--------------------------------------------------------------------------------
/7.最长子序列/LCS.c:
--------------------------------------------------------------------------------
 1 | #include <stdio.h>
 2 | #include <stdlib.h>
 3 | 
 4 | int LCS(char a[],char b[])
 5 | {
 6 |     int i,j;
 7 |     int f[100][100];
 8 |     int la=strlen(a),lb=strlen(b);
 9 |     
10 |     for (i=0;i<=la;i++)
11 |        for (j=0;j<=lb;j++)
12 |        {
13 |            if (i==0 || j==0) f[i][j]=0;
14 |            else if (i>0 && j>0 && a[i]!=b[j])
15 |                 f[i][j]=f[i-1][j]>f[i][j-1]?f[i-1][j]:f[i][j-1];
16 |            else if (i>0 && j>0 && a[i]==b[j])
17 |                 f[i][j]=f[i-1][j-1]+1;
18 |        }   
19 | 
20 |     return f[la][lb];
21 | }
22 | 
23 | int main()
24 | {
25 |     char a[]="1564137";
26 |     char b[]="1168347";
27 |     printf ("%d",LCS(a,b));
28 |     system("pause");
29 |     return 0;   
30 | }
31 | 


--------------------------------------------------------------------------------
/8.数塔问题/shuta.c:
--------------------------------------------------------------------------------
 1 | #include <stdio.h>
 2 | #include <stdlib.h>
 3 | 
 4 | int shuta(int val[5][5])
 5 | {
 6 |     int i,j;
 7 |     int f[100][100];
 8 |     int N = 5;
 9 |     
10 |     for (i=0;i<N;i++)
11 |        f[N-1][i] = val[N-1][i];
12 |     for (i=N-2;i>=0;i--)
13 |        for (j=0;j<=i;j++)
14 |            f[i][j]=(f[i+1][j]>f[i+1][j+1]?f[i+1][j]:f[i+1][j+1]) + val[i][j];
15 |            
16 |     for (i=0;i<N;i++)
17 |     {for (j=0;j<N;j++) printf ("%d ",f[i][j]);       
18 |      printf ("\n");}      
19 |            
20 |     return f[0][0];
21 |     
22 | }
23 | 
24 | int main()
25 | {
26 |     int a[5][5]={{7,0,0,0,0},
27 |                {3,8,0,0,0},
28 |                {8,1,0,0,0},
29 |                {2,7,4,4,0},
30 |                {4,5,2,6,5}};
31 |     printf ("%d",shuta(a));
32 |     system("pause");
33 |     return 0;
34 | }
35 | 


--------------------------------------------------------------------------------
/2.找K大的数/find_k.cpp:
--------------------------------------------------------------------------------
 1 | #include <stdio.h>
 2 | #include <stdlib.h>
 3 | int findNo_k(int a[],int low,int high,int k)
 4 | {
 5 |     int i=low;
 6 |     int j=high;
 7 |     int temp=a[low];
 8 |     
 9 |     while (i<j)
10 |     {
11 |         while (i<j && a[j] >= temp) j--;
12 |         if (i<j) a[i++] = a[j];
13 |         while (i<j && a[i] <= temp) i++;
14 |         if (i<j)  a[j--] = a[i];
15 |     }
16 |     a[i] = temp;
17 |     
18 |     if (i==k-1) printf("%d ", a[i]);
19 |     else if(i<k-1) findNo_k(a,i+1,high,k-i+1);
20 |     else if(i>k-1) findNo_k(a,low,i-1,k);
21 |     
22 |     
23 |     
24 |   //  if (low<i) findNo_k(a,low,i-1,k);
25 |   //  if (high>i) findNo_k(a,i+1,high,k);
26 | }
27 | 
28 | int main()
29 | {
30 |     int a[] = {32,543,5,43,65,43,2,42,47,41};
31 |     int i;
32 |     printf("%d \n",findNo_k(a,0,9,1));
33 |     for (i = 0;i<10;i++)
34 |        printf("%d ",a[i]);
35 |     
36 |     system("pause");
37 |     return 0;
38 | }
39 | 


--------------------------------------------------------------------------------
/3.字典排序/dicsort.cpp:
--------------------------------------------------------------------------------
 1 | #include <iostream>
 2 | #include <string>
 3 | using namespace std;
 4 | 
 5 | int next_permutation(string &str) {
 6 |      int len = str.size();
 7 |      int index = -1;
 8 |      for (int i = len - 2;i > 0;--i) {
 9 |          if (str[i] < str[i + 1]) {
10 |              index = i;
11 |              break;
12 |          }
13 |      }
14 | 
15 |      if (index == -1) return 0;
16 |     
17 |      char ch = 'z'+1;
18 |      
19 |      int num = -1;
20 |      for (int i = index + 1;i < len ;++i) {
21 |          if (str[i] <= str[index]) continue;
22 | 
23 |          if (str[i] < 'z') {
24 |              num = i;
25 |              ch = str[i];
26 |          }
27 |      }
28 |      
29 |      if (num != -1) {
30 |         str[num] = str[index];
31 |         str[index] = ch;
32 |      }
33 |      
34 |      
35 |      for (int i = index + 1;i < len ;++i) { 
36 |          ch = str[i];
37 |          str[i] = str[len-i+index];
38 |          str[len-i+index] = ch;
39 |      }        
40 |      return 1;
41 | }
42 | 
43 | int main()
44 | {
45 |     string input = "3754";
46 |     
47 |     cout << input;
48 |     next_permutation(input);
49 |     cout << endl << input;
50 |     cin >> input;
51 |     return 0;
52 | }
53 | 


--------------------------------------------------------------------------------
/1.KMP/KMP.cpp:
--------------------------------------------------------------------------------
 1 | #include <iostream>
 2 | #include <stdlib.h>
 3 | #include <vector>
 4 | #include <string>
 5 | using namespace std;
 6 | 
 7 | inline void get_next(string T,vector<int> &next)
 8 | {
 9 |     next[0] = -1;
10 |     for(int i=1;i<T.size();i++ ){
11 |         int j = next[i-1];
12 |         while(T[i] != T[j+1] && j>=0 ) j=next[j];
13 |         if(T[i]==T[j+1])next[i]=j+1;
14 |         else next[i]=0;             
15 |     }
16 | };
17 | 
18 | inline string::size_type KMP(const string& S,const string& T)
19 | {
20 |     vector<int> next(T.size());
21 |     get_next(T,next);
22 | 
23 |     string::size_type index,count=0;
24 |     for(index=0;index<S.size();++index){
25 |         int pos=0;
26 |         string::size_type iter=index;
27 |         while(pos<T.size() && iter<S.size()){
28 |             if(S[iter]==T[pos]){
29 |                 ++iter;++pos;
30 |             }
31 |             else{
32 |                  if(pos==0)++iter;
33 |                  else pos=next[pos-1]+1;
34 |             }
35 |         }//while end
36 |         if(pos==T.size()&&(iter-index)==T.size())++count;
37 |     } //for end
38 |     return count;
39 | }
40 | 
41 | int main()
42 | {
43 |     string S="ababcabcacbab";
44 |     string T="abcac";
45 |     string::size_type count = KMP(S,T);
46 |     cout<<count<<endl;
47 |     system("pause");  
48 |     return 0;
49 | }
50 | 


--------------------------------------------------------------------------------
/.gitignore:
--------------------------------------------------------------------------------
  1 | # Executive File
  2 | *.exe
  3 | 
  4 | 
  5 | #################
  6 | ## Eclipse
  7 | #################
  8 | 
  9 | *.pydevproject
 10 | .project
 11 | .metadata
 12 | bin/
 13 | tmp/
 14 | *.tmp
 15 | *.bak
 16 | *.swp
 17 | *~.nib
 18 | local.properties
 19 | .classpath
 20 | .settings/
 21 | .loadpath
 22 | 
 23 | # External tool builders
 24 | .externalToolBuilders/
 25 | 
 26 | # Locally stored "Eclipse launch configurations"
 27 | *.launch
 28 | 
 29 | # CDT-specific
 30 | .cproject
 31 | 
 32 | # PDT-specific
 33 | .buildpath
 34 | 
 35 | 
 36 | #################
 37 | ## Visual Studio
 38 | #################
 39 | 
 40 | ## Ignore Visual Studio temporary files, build results, and
 41 | ## files generated by popular Visual Studio add-ons.
 42 | 
 43 | # User-specific files
 44 | *.suo
 45 | *.user
 46 | *.sln.docstates
 47 | 
 48 | # Build results
 49 | [Dd]ebug/
 50 | [Rr]elease/
 51 | *_i.c
 52 | *_p.c
 53 | *.ilk
 54 | *.meta
 55 | *.obj
 56 | *.pch
 57 | *.pdb
 58 | *.pgc
 59 | *.pgd
 60 | *.rsp
 61 | *.sbr
 62 | *.tlb
 63 | *.tli
 64 | *.tlh
 65 | *.tmp
 66 | *.vspscc
 67 | .builds
 68 | *.dotCover
 69 | 
 70 | ## TODO: If you have NuGet Package Restore enabled, uncomment this
 71 | #packages/
 72 | 
 73 | # Visual C++ cache files
 74 | ipch/
 75 | *.aps
 76 | *.ncb
 77 | *.opensdf
 78 | *.sdf
 79 | 
 80 | # Visual Studio profiler
 81 | *.psess
 82 | *.vsp
 83 | 
 84 | # ReSharper is a .NET coding add-in
 85 | _ReSharper*
 86 | 
 87 | # Installshield output folder
 88 | [Ee]xpress
 89 | 
 90 | # DocProject is a documentation generator add-in
 91 | DocProject/buildhelp/
 92 | DocProject/Help/*.HxT
 93 | DocProject/Help/*.HxC
 94 | DocProject/Help/*.hhc
 95 | DocProject/Help/*.hhk
 96 | DocProject/Help/*.hhp
 97 | DocProject/Help/Html2
 98 | DocProject/Help/html
 99 | 
100 | # Click-Once directory
101 | publish
102 | 
103 | # Others
104 | [Bb]in
105 | [Oo]bj
106 | sql
107 | TestResults
108 | *.Cache
109 | ClientBin
110 | stylecop.*
111 | ~$*
112 | *.dbmdl
113 | Generated_Code #added for RIA/Silverlight projects
114 | 
115 | # Backup & report files from converting an old project file to a newer
116 | # Visual Studio version. Backup files are not needed, because we have git ;-)
117 | _UpgradeReport_Files/
118 | Backup*/
119 | UpgradeLog*.XML
120 | 
121 | 
122 | 
123 | ############
124 | ## Windows
125 | ############
126 | 
127 | # Windows image file caches
128 | Thumbs.db
129 | 
130 | # Folder config file
131 | Desktop.ini
132 | 
133 | 
134 | #############
135 | ## Python
136 | #############
137 | 
138 | *.py[co]
139 | 
140 | # Packages
141 | *.egg
142 | *.egg-info
143 | dist
144 | build
145 | eggs
146 | parts
147 | bin
148 | var
149 | sdist
150 | develop-eggs
151 | .installed.cfg
152 | 
153 | # Installer logs
154 | pip-log.txt
155 | 
156 | # Unit test / coverage reports
157 | .coverage
158 | .tox
159 | 
160 | #Translations
161 | *.mo
162 | 
163 | #Mr Developer
164 | .mr.developer.cfg
165 | 
166 | # Mac crap
167 | .DS_Store
168 | 


--------------------------------------------------------------------------------
/4.简单的社交关系映射/friend.cpp:
--------------------------------------------------------------------------------
  1 | #include <iostream>
  2 | #include <string>
  3 | #include <stdexcept>
  4 | #include <stdio.h>
  5 | #include <stdlib.h>
  6 | #include <vector>
  7 | using namespace std;
  8 | 
  9 | #define MAX_VERTEX_NUM 100
 10 | 
 11 | 
 12 | class User {
 13 | 	static unsigned id_auto;
 14 | public :
 15 | 	unsigned id;
 16 | 	string username;
 17 | 	string password;
 18 | 	string duty;
 19 | 	User(string &u,string &p,string &d);
 20 | 	void displsy();
 21 | };
 22 | unsigned User::id_auto = 0;
 23 | 
 24 | User::User(string &u, string &p, string &d){
 25 | 	if (u.length() == 0) throw runtime_error("u length error");
 26 | 	if (p.length() == 0) throw runtime_error("p length error");
 27 | 	if (d.length() == 0) throw runtime_error("d length error");
 28 | 	username = u;
 29 | 	password = p;
 30 | 	duty = d;
 31 | 	id = ++id_auto;
 32 | }
 33 | 
 34 | 
 35 | void User::displsy() {
 36 | 	cout << "id=" << id<<" username="<<username<<" duty="<<duty<<endl;
 37 | }
 38 | 
 39 | 
 40 | 
 41 | typedef enum{DG,DN,UDG,UDN} GraphKind;
 42 | 
 43 | class AdjMatrix {   
 44 | 	vector<User*> vexs;
 45 | 	int arcs[MAX_VERTEX_NUM][MAX_VERTEX_NUM];
 46 | 	int vexnum,arcnum;
 47 | 	GraphKind kind;
 48 | 	friend class Operations;
 49 | public:
 50 | 	AdjMatrix();
 51 | 	int AddVex(User *vex);
 52 | 	int AddArc(int i,int j);
 53 | 	void display();
 54 | };
 55 | 
 56 | AdjMatrix::AdjMatrix() {
 57 | 	vexnum = 0;
 58 | 	arcnum = 0;
 59 | 	for (int i = 0;i < MAX_VERTEX_NUM;i++)
 60 | 	{
 61 | 		kind = UDG;
 62 | 		for (int j = 0;j < MAX_VERTEX_NUM;j++)
 63 | 		{
 64 | 			arcs[i][j] = 0;
 65 | 		}
 66 | 	//	arcs[i][i] = 1;
 67 | 	}
 68 | }
 69 | 
 70 | int AdjMatrix::AddVex(User *vex){
 71 | 	vexs.push_back(vex);
 72 | 	vexnum++;
 73 | 	return 0;
 74 | }
 75 | 
 76 | int AdjMatrix::AddArc(int i,int j){
 77 | 	arcs[i][j] = arcs[j][i] = 1;
 78 | 	arcnum++;
 79 | 	return 0;
 80 | }
 81 | 
 82 | void AdjMatrix::display(){
 83 | 	/*for (int i = 0;i < vexnum;i++)
 84 | 	{
 85 | 		for (int j = 0;j < vexnum;j++)
 86 | 		{
 87 | 			cout << arcs[i][j] << ' ';
 88 | 		}
 89 | 		cout << endl;
 90 | 	}*/
 91 | 	
 92 | 	for (vector<User*>::iterator iter = vexs.begin();iter != vexs.end();++iter){
 93 | 		(*iter)->displsy();
 94 | 	}
 95 | }
 96 | 
 97 | class Operations {
 98 | 	AdjMatrix *g;
 99 | public:
100 | 	User *currentUser;
101 | 	Operations(AdjMatrix *G):currentUser(NULL),g(G){}
102 | 	int Login();
103 | 	int Register();
104 | 	void Logout();
105 | 	void show_menu();
106 | 	void show_operations();
107 | 	void makeFriend();
108 | 	void showPeople();
109 | 	void myFriend();
110 | 	int userIsExist(string &user);
111 | 	int userIsMyFriendByID(int id);
112 | 	User *getUserByUsername(string &user);
113 | };
114 | 
115 | int Operations::Login(){
116 | 	
117 | 	cout << "Login as:";
118 | 	string buffer;
119 | 	fflush(stdin);
120 | 	cin >> buffer;
121 | 	if(!userIsExist(buffer)) {
122 | 		cout << buffer << " isn't exist!" << endl;
123 | 		show_menu();
124 | 		return 0;
125 | 	}
126 | 	User *user = getUserByUsername(buffer);
127 | 
128 | 	Again: 
129 | 	cout << "Password:";
130 | 	fflush(stdin);
131 | 	cin >> buffer;
132 | 	if (user->password != buffer)
133 | 	{
134 | 		cout << "Access Denied" << endl;
135 | 		goto Again;
136 | 	}
137 | 	currentUser = user;
138 | 	return 1;
139 | }
140 | 
141 | int Operations::Register() {
142 | 	string username;
143 | 	string password;
144 | 	string cpassword;
145 | 	string duty;
146 | 	uAgain:
147 | 	cout << "Enter Username:";
148 | 	fflush(stdin);
149 | 	cin >> username;
150 | 	if(userIsExist(username)) {
151 | 		cout << username << " has existed!" << endl;
152 | 		goto uAgain;
153 | 	}
154 | 	cout << "Enter Password:";
155 | 	fflush(stdin);
156 | 	cin >> password;
157 | 	cAgain:
158 | 	cout << "Confirm Password:";
159 | 	fflush(stdin);
160 | 	cin >> cpassword;
161 | 	if (password != cpassword) {
162 | 		cout << "error - not the same!" << endl;
163 | 		goto cAgain;
164 | 	}
165 | 	cout << "Enter Duty:";
166 | 	fflush(stdin);
167 | 	cin >> duty;
168 | 
169 | 	User *user = new User(username,password,duty);
170 | 	g->AddVex(user);
171 | 	return 1;
172 | }
173 | 
174 | void Operations::Logout() {
175 | 	currentUser = NULL;
176 | }
177 | 
178 | void Operations::makeFriend() {
179 | 	int id;
180 | 	cout << "ID of your friend who you want to make:";
181 | 	fflush (stdin);
182 | 	cin >> id;
183 | 	if (currentUser->id == id) {
184 | 		cout << "Never kiss your own ass!" << endl;
185 | 		return ;
186 | 	}
187 | 	if (userIsMyFriendByID(id)) {
188 | 		cout << "This guy had been your friend yet!" << endl;
189 | 		return ;
190 | 	}
191 | 	g->AddArc(currentUser->id-1,id-1);
192 | 	cout << "OK,you are friend now!" << endl;
193 | }
194 | void Operations::showPeople() {
195 | 	g->display();
196 | }
197 | void Operations::myFriend() {
198 | 	int id = currentUser->id;
199 | 	for (int i = 0;i < g->vexnum;i++)
200 | 	{
201 | 		if(g->arcs[id-1][i]) {
202 | 			g->vexs[i]->displsy();
203 | 		}
204 | 	}
205 | }
206 | 
207 | int Operations::userIsExist(string &user) {
208 | 	for (vector<User*>::iterator iter = g->vexs.begin();iter != g->vexs.end();++iter){
209 | 		if (user == (*iter)->username) return 1;
210 | 	}
211 | 	return 0;
212 | }
213 | 
214 | int Operations::userIsMyFriendByID(int id){
215 | 	int myid = currentUser->id;
216 | 	return g->arcs[myid-1][id-1];
217 | }
218 | 
219 | User *Operations::getUserByUsername(string &user) {
220 | 	for (vector<User*>::iterator iter = g->vexs.begin();iter != g->vexs.end();++iter){
221 | 		if (user == (*iter)->username) return *iter;
222 | 	}
223 | 	return NULL;
224 | }
225 | 
226 | void Operations::show_menu(){
227 | 	cout << "======================================================" << endl;
228 | 	cout << "==   1.Login     2.Register     3.Exit              ==" << endl;
229 | 	cout << "======================================================" << endl;
230 | }
231 | 
232 | void Operations::show_operations() {
233 | 	cout << "=====================================================================" << endl;
234 | 	cout << "==  1.My friend   2.Show people  3.Make friend  4.Logout  5.Exit   ==" << endl;
235 | 	cout << "=====================================================================" << endl;
236 | }
237 | 
238 | int main()
239 | {
240 | 	AdjMatrix G;
241 | 	User *user[5];
242 | 	try {
243 | 		user[0] = new User(string("Obama"),string("111"),string("USA Present"));
244 | 		user[1] = new User(string("HuGe"),string("222"),string("China Chairman"));
245 | 		user[2] = new User(string("PuJing"),string("333"),string("Russia Present"));
246 | 		user[3] = new User(string("Hitler"),string("444"),string("Genmany Present"));
247 | 		user[4] = new User(string("LinKen"),string("555"),string("USA Old Present"));
248 | 	}catch(runtime_error e){
249 | 		cout << e.what() << endl;
250 | 	}
251 | 
252 | 	for (int i = 0;i < 5;i++)
253 | 	{
254 | 		G.AddVex(user[i]);
255 | 	}
256 | 	G.AddArc(0,1);
257 | 	G.AddArc(0,2);
258 | 	G.AddArc(0,4);
259 | 	G.AddArc(1,3);
260 | 	G.AddArc(2,3);
261 | 	
262 | 
263 | 	Operations op(&G);
264 | 	
265 | 	string buf = "";
266 | 	int ch;
267 | 	while(1) {
268 | 		if (buf.length() && op.currentUser) {
269 | 			op.show_operations();
270 | 			cout << buf;
271 | 			cin >> ch;
272 | 			switch (ch)
273 | 			{
274 | 			case 1:
275 | 				op.myFriend();
276 | 				break;
277 | 			case 2:
278 | 				op.showPeople();
279 | 				break;
280 | 			case 3:
281 | 				op.makeFriend();
282 | 				break;
283 | 			case 4:
284 | 				op.Logout();
285 | 				buf = "";
286 | 				break;
287 | 			case 5:
288 | 				exit(0);
289 | 				break;
290 | 			default:
291 | 				break;
292 | 			}
293 | 		}
294 | 		else {
295 | 			op.show_menu();
296 | 			cout << "Not Logged In:";
297 | 			cin >> ch;
298 | 			switch (ch)
299 | 			{
300 | 			case 1:
301 | 				if(op.Login()) buf = op.currentUser->username+":";
302 | 				break;
303 | 			case 2:
304 | 				op.Register();
305 | 				break;
306 | 			case 3:
307 | 				exit(0);
308 | 				break;
309 | 			default:
310 | 				break;
311 | 			}
312 | 		}
313 | 	}
314 | 	system("pause");
315 | 	return 0;
316 | }
317 | 


--------------------------------------------------------------------------------