View Compilation Error

0_0_14463690_22104.cpp: In function 'int main()':
0_0_14463690_22104.cpp:118:16: error: 'strlen' was not declared in this scope
   if(s[strlen(s)-1] = '\n')
                ^
0_0_14463690_22104.cpp:129:26: error: 'strlen' was not declared in this scope
   int len = strlen(str[i]);
                          ^
0_0_14463690_22104.cpp:131:34: error: 'strncpy_s' was not declared in this scope
    strncpy_s(left, 110, str[i], j);
                                  ^
0_0_14463690_22104.cpp:133:32: error: 'strcpy_s' was not declared in this scope
    strcpy_s(right,110, str[i]+j);
                                ^