/in/foo.cc: In function 'int main()':
/in/foo.cc:6:48: error: 'strcmp' was not declared in this scope
  while (cin.getline(a,100) && strcmp(a,"000000")!=0) {
                                                ^
/in/foo.cc:7:17: error: 'strlen' was not declared in this scope
   len = strlen(a); t = 0;
                 ^
/in/foo.cc:15:25: error: 'strncpy_s' was not declared in this scope
    strncpy_s(b, a + i, 3);
                         ^
/in/foo.cc:17:41: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
    if (a[i] == a[len - i - 1]||a[i]=='('&&a[len-i-1]==')'||a[i]=='{'&&a[len-i-1]=='}'||a[i]=='['&&a[len-i-1]==']')
                                         ^
/in/foo.cc:17:69: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
    if (a[i] == a[len - i - 1]||a[i]=='('&&a[len-i-1]==')'||a[i]=='{'&&a[len-i-1]=='}'||a[i]=='['&&a[len-i-1]==']')
                                                                     ^
/in/foo.cc:17:97: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
    if (a[i] == a[len - i - 1]||a[i]=='('&&a[len-i-1]==')'||a[i]=='{'&&a[len-i-1]=='}'||a[i]=='['&&a[len-i-1]==']')
                                                                                                 ^