View Compilation Error

0_0_20319921_9642.cpp: In function 'bool ju(int)':
0_0_20319921_9642.cpp:30:41: error: 'strlen' was not declared in this scope
  size_t cl = c.size(), sl = strlen(ss[i]);
                                         ^
0_0_20319921_9642.cpp: In function 'void add(int)':
0_0_20319921_9642.cpp:65:24: error: 'strlen' was not declared in this scope
  size_t cl = strlen(P_C), sl = strlen(ss[x]);
                        ^
0_0_20319921_9642.cpp:66:16: error: 'sl' was not declared in this scope
  for (i = 0; i<sl; i++) O_O[i] = ss[x][sl - i - 1] - 48;
                ^
0_0_20319921_9642.cpp:68:6: error: 'sl' was not declared in this scope
  if (sl>cl) cl = sl;
      ^
0_0_20319921_9642.cpp: In member function 'void int128::pr()':
0_0_20319921_9642.cpp:88:29: error: 'memset' was not declared in this scope
   memset(P_C, 0, sizeof(P_C));
                             ^