View Compilation Error

0_0_36706309_10600.cpp: In function 'int main()':
0_0_36706309_10600.cpp:19:18: error: 'strlen' was not declared in this scope
 ll len = strlen(a);
                  ^
0_0_36706309_10600.cpp:23:26: error: 'strncmp' was not declared in this scope
 if (strncmp(a, a+len-i, i) == 0) ga |= (ll)1 << i;
                          ^
0_0_36706309_10600.cpp:24:26: error: 'strncmp' was not declared in this scope
 if (strncmp(a, b+len-i, i) == 0) fa |= (ll)1 << i;
                          ^
0_0_36706309_10600.cpp:25:26: error: 'strncmp' was not declared in this scope
 if (strncmp(b, a+len-i, i) == 0) gb |= (ll)1 << i;
                          ^
0_0_36706309_10600.cpp:26:26: error: 'strncmp' was not declared in this scope
 if (strncmp(b, b+len-i, i) == 0) fb |= (ll)1 << i;
                          ^