Yukicoderにしてはちょっと定数倍厳しいなと思ったら非想定解だったぽい。 想定解の方が綺麗。

## solution

segment木。$O(HW + Q (H \log W + W \log H))$。

## implementation

#include <iostream>
#include <vector>
#include <functional>
#include <cmath>
#define repeat(i,n) for (int i = 0; (i) < int(n); ++(i))
#define repeat_from(i,m,n) for (int i = (m); (i) < int(n); ++(i))
using ll = long long;
using namespace std;

template <typename T>
struct segment_tree { // on monoid
int n;
vector<T> a;
function<T (T,T)> append; // associative
T unit; // unit
segment_tree() = default;
segment_tree(int a_n, T a_unit, function<T (T,T)> a_append) {
n = pow(2,ceil(log2(a_n)));
a.resize(2*n-1, a_unit);
unit = a_unit;
append = a_append;
}
void point_update(int i, T z) {
a[i+n-1] = z;
for (i = (i+n)/2; i > 0; i /= 2) {
a[i-1] = append(a[2*i-1], a[2*i]);
}
}
T range_concat(int l, int r) {
return range_concat(0, 0, n, l, r);
}
T range_concat(int i, int il, int ir, int l, int r) {
if (l <= il and ir <= r) {
return a[i];
} else if (ir <= l or r <= il) {
return unit;
} else {
return append(
range_concat(2*i+1, il, (il+ir)/2, l, r),
range_concat(2*i+2, (il+ir)/2, ir, l, r));
}
}
};
int nc2(int n) { return n*(n-1)/2; }

struct cww_t {
int c, w, cw, wc, cww, wwc;
};
const cww_t unit = {};
cww_t append(cww_t const & x, cww_t const & y) {
cww_t z;
z.c = x.c + y.c;
z.w = x.w + y.w;
z.cw = x.cw + x.c * y.w + y.cw;
z.wc = x.wc + x.w * y.c + y.wc;
z.cww = x.cww + x.cw * y.w + x.c * nc2(y.w) + y.cww;
z.wwc = x.wwc + nc2(x.w) * y.c + x.w * y.wc + y.wwc;
return z;
}
int main() {
int h, w; cin >> h >> w;
vector<string> f(h); repeat (y,h) cin >> f[y];
vector<segment_tree<cww_t> > segtree_hr(h, segment_tree<cww_t>(w, unit, append));
vector<segment_tree<cww_t> > segtree_vt(w, segment_tree<cww_t>(h, unit, append));
repeat (y,h) repeat (x,w) segtree_hr[y].point_update(x, (cww_t) { (f[y][x] == 'c'), (f[y][x] == 'w'), 0, 0 });
repeat (x,w) repeat (y,h) segtree_vt[x].point_update(y, (cww_t) { (f[y][x] == 'c'), (f[y][x] == 'w'), 0, 0 });
int q; cin >> q;
while (q --) {
int ly, lx, ry, rx; cin >> ly >> lx >> ry >> rx; -- ly; -- lx;
ll ans = 0;
repeat_from (y,ly,ry) { auto it = segtree_hr[y].range_concat(lx, rx); ans += it.cww + it.wwc; }
repeat_from (x,lx,rx) { auto it = segtree_vt[x].range_concat(ly, ry); ans += it.cww + it.wwc; }
cout << ans << endl;
}
return 0;
}