#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using ull = unsigned long long;
#define all(x) x.begin(), x.end()
template <typename T1, typename T2> inline void chkmin(T1 &x, const T2 & y) {if (x > y) x = y;}
template <typename T1, typename T2> inline void chkmax(T1 &x, const T2 & y) {if (x < y) x = y;}
const int MAXN = 3010;
int n, m;
char table[MAXN][MAXN];
void read() {
cin >> n >> m;
for (int i = 0; i < n; i++) {
for (int j = 0; j < m; j++) {
cin >> table[i][j];
}
}
}
ll ans;
int dp[MAXN][MAXN][2];
void build() {
for (int i = 0; i < n; i++) {
dp[i][m - 1][0] = table[i][m - 1][0] == 'O';
for (int j = m - 2; j >= 0; j--) {
dp[i][j][0] = dp[i][j + 1][0] + table[i][j] == 'O';
}
}
for (int j = 0; j < m; j++) {
dp[n - 1][j][1] = table[n - 1][j] == 'I';
for (int i = n - 2; i >= 0; i--) {
dp[i][j][1] = dp[i + 1][j][1] + table[i][j] == 'I';
}
}
}
void calc() {
ans = 0;
for (int i = 0; i < n; i++) {
for (int j = 0; j < m; j++) {
if (table[i][j] == 'J') {
ans += dp[i][j][0] * dp[i][j][1];
}
}
}
}
void run() {
build();
calc();
}
void write() {
cout << ans << endl;
}
signed main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
read();
run();
write();
return 0;
}
Compilation message
joi2019_ho_t1.cpp: In function 'void build()':
joi2019_ho_t1.cpp:31:38: error: invalid types 'char[int]' for array subscript
dp[i][m - 1][0] = table[i][m - 1][0] == 'O';
^
