joi2019_ho_t1.cpp:2:20: warning: extra tokens at end of #include directive
2 | #include <cstring> using namespace std; const int N = 3030;int O[N][N];int I[N][N];string s[N];int n, m; void input(){ cin >> n >> m; for (int i = 0; i < n; ++i){ cin >> s[i]; } } void preprocess(){ for (int i = 0; i < n; ++i){ O[i][m] = 0; for (int j = m - 1; j >= 0; --j){ O[i][j] = O[i][j + 1]; if (s[i][j] == 'O'){ ++O[i][j]; } } } for (int j = 0; j < m; ++j){ I[n][j] = 0; for (int i = n - 1; i >= 0; --i){ I[i][j] = I[i + 1][j]; if (s[i][j] == 'I'){ ++I[i][j]; } } }} int solve(){ long long ans = 0; for (int i = 0; i < n; ++i){ for (int j = 0; j < m; ++j){ if (s[i][j] == 'J'){ ans += O[i][j] * I[i][j]; } } } return ans;} int main(){ input(); preprocess(); cout << solve();}
| ^~~~~
/usr/bin/ld: /usr/lib/gcc/x86_64-linux-gnu/10/../../../x86_64-linux-gnu/crt1.o: in function `_start':
(.text+0x24): undefined reference to `main'
collect2: error: ld returned 1 exit status