View Compilation Error

0_0_21039556_4753.cpp: In function 'int main(int, char**)':
0_0_21039556_4753.cpp:55:21: error: 'strcmp' was not declared in this scope
  if (strcmp(str, "0") == 0) break;
                     ^
0_0_21039556_4753.cpp:56:18: error: 'strlen' was not declared in this scope
  Len = strlen(str);
                  ^