BZOJ1452: [JSOI2009]Count

Posted 2020-10-24 mt-li

Description

Input

Output

Sample Input

Sample Output

1
2

HINT

 

 

题目传送门

 

话说这好像是我第一次做树状数组的题

树状数组裸题，还是二维的，多一层for而已

 

代码如下：

#include<cmath>
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<algorithm>
using namespace std;
int a[310][310][110];
int c[310][310];
int n,m;
int lowbit(int x){return x&-x;}
void change(int x,int y,int cc,int d)
{
    for(int i=x;i<=n;i+=lowbit(i))
        for(int j=y;j<=m;j+=lowbit(j))
            a[i][j][cc]+=d;
}
/*
3 3
1 2 3
3 2 2
2 1 3
*/
int findsum(int x,int y,int cc)
{
    int sum=0;
    for(int i=x;i>=1;i-=lowbit(i))
        for(int j=y;j>=1;j-=lowbit(j))
            sum+=a[i][j][cc];
    return sum;
}
int main()
{
    scanf("%d%d",&n,&m);
    for(int i=1;i<=n;i++)
        for(int j=1;j<=m;j++)
        {
            scanf("%d",&c[i][j]);
            change(i,j,c[i][j],1);
        }
    int Q;
    scanf("%d",&Q);
    while(Q--)
    {
        int k,x,y,cc,tx,ty;
        scanf("%d",&k);
        if(k==1)
        {
            scanf("%d%d%d",&x,&y,&cc);
            change(x,y,c[x][y],-1);
            c[x][y]=cc;
            change(x,y,c[x][y],1);
        }
        else
        {
            scanf("%d%d%d%d%d",&x,&tx,&y,&ty,&cc);
            int ans;
            ans=findsum(tx,ty,cc)+findsum(x-1,y-1,cc);
            ans=ans-(findsum(x-1,ty,cc)+findsum(tx,y-1,cc));
            printf("%d\n",ans);
        }
    }
    return 0;
}

by_lmy