View Compilation Error

0_0_39220374_8679.c: In function 'main':
0_0_39220374_8679.c:6:23: error: expected declaration specifiers or '...' before numeric constant
    6 |         double m, ans(0);
      |                       ^
0_0_39220374_8679.c:7:9: error: 'cin' undeclared (first use in this function)
    7 |         cin >> t >> n >> m;
      |         ^~~
0_0_39220374_8679.c:7:9: note: each undeclared identifier is reported only once for each function it appears in
0_0_39220374_8679.c:12:13: error: 'ans' undeclared (first use in this function)
   12 |             ans += x * (100 - y) / 100.0;
      |             ^~~
0_0_39220374_8679.c:14:20: error: 'cout' undeclared (first use in this function)
   14 |         if (i != 1)cout << '\n';
      |                    ^~~~