二维树状数组 BZOJ 1452 [JSOI2009]Count

#include <bits/stdc++.h>

const int N = 305;
struct BIT_2D {
int c[105]

, n, m;
void init(int n, int m) {
memset (c, 0, sizeof (c));
this->n = n;
this->m = m;
}
void updata(int k, int x, int y, int z) {
for (int i=x; i<=n; i+=i&(-i)) {
for (int j=y; j<=m; j+=j&(-j)) {
c[k][i][j] += z;
}
}
}
int query(int k, int x, int y) {
int ret = 0;
for (int i=x; i; i-=i&(-i)) {
for (int j=y; j; j-=j&(-j)) {
ret += c[k][i][j];
}
}
return ret;
}
int count(int x1, int x2, int y1, int y2, int a) {
return query (a, x2, y2) - query (a, x2, y1-1) - query (a, x1-1, y2) + query (a, x1-1, y1-1);
}
};

int a

;
BIT_2D bit;

int read() {
int ret = 0, f = 1;
char ch = getchar ();
while (ch < '0' || ch > '9') {
if (ch == '-') {
f = -1;
}
ch = getchar ();
}
while (ch >= '0' && ch <= '9') {
ret = ret * 10 + ch - '0';
ch = getchar ();
}
return ret * f;
}

int main() {
int n, m;
while (scanf ("%d%d", &n, &m) == 2) {
bit.init (n, m);
for (int i=1; i<=n; ++i) {
for (int j=1; j<=m; ++j) {
//scanf ("%d", &a[i][j]);
a[i][j] = read ();
bit.updata (a[i][j], i, j, 1);
}
}
int q;
scanf ("%d", &q);
while (q--) {
int op, x1, x2, y1, y2, x;
scanf ("%d", &op);
if (op == 1) {
//scanf ("%d%d%d", &x1, &y1, &x);
x1 = read (); y1 = read (); x = read ();
bit.updata (a[x1][y1], x1, y1, -1);
a[x1][y1] = x;
bit.updata (a[x1][y1], x1, y1, 1);
} else {
//scanf ("%d%d%d%d%d", &x1, &x2, &y1, &y2, &x);
x1 = read (); x2 = read (); y1 = read (); y2 = read (); x = read ();
printf ("%d\n", bit.count (x1, x2, y1, y2, x));
}
}
}
return 0;
}