洛谷P4054 [JSOI2009]计数问题(二维树状数组)

题意

题目链接

Sol

很傻x的题。。

c才100, n, m才300，直接开100个二维树状数组就做完了。。

#include<bits/stdc++.h>
using namespace std;
const int MAXN = 301;
inline int read() {
    char c = getchar(); int x = 0, f = 1;
    while(c < '0' || c > '9') {if(c == '-') f = -1; c = getchar();}
    while(c >= '0' && c <= '9') x = x * 10 + c - '0', c = getchar();
    return x * f;
}
int N, M, col[MAXN][MAXN];
struct BIT {
#define lb(x) (x & (-x))
    int T[MAXN][MAXN];
    void Add(int x, int y, int v) {
        for(int i = x; i <= N; i += lb(i))
            for(int j = y; j <= M; j += lb(j))
                T[i][j] += v;
    }
    int sum(int x, int y) {
        int ans = 0;
        for(int i = x; i; i -= lb(i))
            for(int j = y; j; j -= lb(j))
                ans += T[i][j];
        return ans;
    }
    int Query(int x1, int x2, int y1, int y2) {
        return sum(x2, y2) - sum(x1 - 1, y2) - sum(x2, y1 - 1) + sum(x1 - 1, y1 - 1);
    }
}T[101];
int main() {
    N = read(); M = read();
    for(int i = 1; i <= N; i++) 
        for(int j = 1; j <= M; j++) 
            T[col[i][j] = read()].Add(i, j, 1);
    int Q = read();
    while(Q--) {
        int opt = read(), a = read(), b = read(), c = read(), d, e;
        if(opt == 1) T[col[a][b]].Add(a, b, -1), T[col[a][b] = c].Add(a, b, 1);
        if(opt == 2) d = read(), e = read(), printf("%d\n", T[e].Query(a, b, c, d));
    }
    return 0;
}

标签：洛谷,树状,int,JSOI2009,while,P4054,二维,100,getchar
来源： https://www.cnblogs.com/zwfymqz/p/10352718.html