View Compilation Error

0_0_34392670_30831.cpp: In function 'void getFail(char*)':
0_0_34392670_30831.cpp:11:24: error: 'strlen' was not declared in this scope
      int len = strlen(p);
                        ^
0_0_34392670_30831.cpp: In function 'int KMP(char*, char*)':
0_0_34392670_30831.cpp:24:24: error: 'strlen' was not declared in this scope
     int lent = strlen(t),lenp = strlen(p);
                        ^
0_0_34392670_30831.cpp:29:21: error: 'lenp' was not declared in this scope
             if(j == lenp) return 1;
                     ^
0_0_34392670_30831.cpp: In function 'int get_min(char*)':
0_0_34392670_30831.cpp:38:23: error: 'strlen' was not declared in this scope
     int len = strlen(p);
                       ^
0_0_34392670_30831.cpp: In function 'int get_max(char*)':
0_0_34392670_30831.cpp:55:23: error: 'strlen' was not declared in this scope
     int len = strlen(p);
                       ^
0_0_34392670_30831.cpp: In function 'int main()':
0_0_34392670_30831.cpp:73:27: error: 'strlen' was not declared in this scope
         int len = strlen(s);
                           ^