3
4
裸的二维树状数组。
所求区域和 sum = sum(R, T) – sum(R,B-1) – sum(L-1,T) + sum(L-1,B-1)
注意S及 坐标 应从1开始，所以应对输入坐标做 +1处理。
#include <cstdio>
#include <iostream>
#include <algorithm>
#include <string.h>
using namespace std;
#define S 1030
int c[S][S];
int n;
int lowbit(int x)
{
return x&(-x);
}
void Updata(int x,int y,int val)
{
for(int i=x; i<=n; i+=lowbit(i))
{
for(int j=y; j<=n; j+=lowbit(j))
{
c[i][j]+=val;
}
}
}
int Getsum(int x,int y)
{
int sum=0;
for(int i=x; i>0; i-=lowbit(i))
{
for(int j=y; j>0; j-=lowbit(j))
{
sum+=c[i][j];
}
}
return sum;
}
int main()
{
int tt, cmd, x, y, val;
int x1, y1, x2, y2;
freopen("B.in","r",stdin);
freopen("X.out","w",stdout);
scanf("%d%d",&tt,&n);
memset(c,0,sizeof(c));
while(scanf("%d",&cmd) && cmd<3)
{
if(cmd==1)
{
scanf("%d%d%d",&x,&y,&val);
x++;
y++;
Updata(x,y,val);
}
else if(cmd==2)
{
scanf("%d%d%d%d",&x1,&y1,&x2,&y2);
x1++, y1++, x2++, y2++;
int ans=Getsum(x2,y2)-Getsum(x2,y1-1)-Getsum(x1-1,y2)+Getsum(x1-1,y1-1);
printf("%d\n",ans);
}
}
return 0;
}
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