c/c++语言开发共享洛谷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("%dn", t[e].query(a, b, c, d));     }     return 0; }