二维树状数组用于求子矩阵的和。
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1 /* 2 Author:Zhaofa Fang 3 Lang:C++ 4 */ 5 #include <cstdio> 6 #include <cstdlib> 7 #include <iostream> 8 #include <cmath> 9 #include <cstring> 10 #include <algorithm> 11 #include <string> 12 #include <utility> 13 #include <vector> 14 #include <queue> 15 #include <stack> 16 #include <map> 17 #include <set> 18 using namespace std; 19 typedef long long ll; 20 #define pii pair<int,int> 21 #define pb push_back 22 #define mp make_pair 23 #define fi first 24 #define se second 25 #define lowbit(x) (x&(-x)) 26 #define INF (1<<30) 27 28 const int maxn = 1025; 29 int c[maxn][maxn]; 30 int n; 31 void add(int x,int y,int v) 32 { 33 for(int i=x;i<=n;i+=lowbit(i)) 34 for(int j=y;j<=n;j+=lowbit(j)) 35 c[i][j] += v; 36 } 37 int sum(int x,int y) 38 { 39 int res = 0; 40 for(int i=x;i>0;i-=lowbit(i)) 41 for(int j=y;j>0;j-=lowbit(j)) 42 res += c[i][j]; 43 return res; 44 } 45 int main() 46 { 47 #ifndef ONLINE_JUDGE 48 freopen("in","r",stdin); 49 #endif 50 int op; 51 while(~scanf("%d",&op)) 52 { 53 if(op == 0) 54 { 55 scanf("%d",&n); 56 memset(c,0,sizeof(c)); 57 } 58 else if(op == 1) 59 { 60 int x,y,a; 61 scanf("%d%d%d",&x,&y,&a); 62 add(x+1,y+1,a); 63 } 64 else if(op == 2) 65 { 66 int l,b,r,t; 67 scanf("%d%d%d%d",&l,&b,&r,&t); 68 printf("%d\n",sum(r+1,t+1)+sum(l,b)-sum(l,t+1)-sum(r+1,b)); 69 } 70 else break; 71 } 72 return 0; 73 }