View Compilation Error

0_0_15169925_19490.cpp: In function 'bool solve()':
0_0_15169925_19490.cpp:112:16: error: 'strlen' was not declared in this scope
  na = strlen(sa); nb = strlen(sb);
                ^
0_0_15169925_19490.cpp:120:31: error: 'memset' was not declared in this scope
  memset(sc, 0, sizeof(char)*nc);
                               ^