poj 1195 二维树状数组 及二维树状数组模板

http://poj.org/problem?id=1195

求矩阵和的时候，下标弄错WA了一次...

求矩形(x1,y1) （x2,y2）的sum
|sum=sum(x2,y2)-sum(x1-1,y2)-sum(x2,y1-1)+sum(x1-1,y1-1)

二维树状数组讲解：http://blog.csdn.net/u011026968/article/details/38532117

二维树状数组模板：

/*==================================================*\
| 二维树状数组
| 1、初始化：INIT: c[][]置为0; Row,Col要赋初值
| 数组下标一定要从1开始!!!!!!!!!
| 2、sum(i,j) 前i行前j列的和，update(i,j,num)
| 将(i,j)加上num
| 3、求矩形(x1,y1) （x2,y2）的sum
|sum=sum(x2,y2)-sum(x1-1,y2)-sum(x2,y1-1)+sum(x1-1,y1-1)
|注意Sum和c 必要的时候用long long
\*==================================================*/
const int N = 10000;
int c[N][N]; int Row, Col;
inline int Lowbit(const int &x){// x > 0
    return x&(-x);
}
int Sum(int i,int j){
    int tempj, sum = 0;
    while( i > 0 ){
        tempj= j;
        while( tempj > 0 ){
            sum += c[i][tempj];
            tempj -= Lowbit(tempj);
        }
        i -= Lowbit(i);
    }
    return sum;
}
void Update(int i, int j, int num){
    int tempj;
    while( i <= Row ){
        tempj = j;
        while( tempj <= Col ){
        c[i][tempj] += num;
        tempj += Lowbit(tempj);
        }
        i += Lowbit(i);
    }
}

poj 1195 代码

#include <cstdio>
#include <cstring>
#include <algorithm>
#include <string>
#include <iostream>
#include <cmath>
#include <map>
#include <set>
#include <queue>
using namespace std;

#define ls(rt) rt*2
#define rs(rt) rt*2+1
#define ll long long
#define ull unsigned long long
#define rep(i,s,e) for(int i=s;i<e;i++)
#define repe(i,s,e) for(int i=s;i<=e;i++)
#define CL(a,b) memset(a,b,sizeof(a))
#define IN(s) freopen(s,"r",stdin)
#define OUT(s) freopen(s,"w",stdout)

const int MAXN = 1024 +100;
ll c[MAXN][MAXN];
int row,col;
inline int lowbit(int i){return i&(-i);}
ll sum(int i, int j)
{
    int tmpj;
    ll ret=0;
    while(i>0)
    {
        tmpj=j;
        while(tmpj>0)
        {
            ret+=c[i][tmpj];
            tmpj-=lowbit(tmpj);
        }
        i-=lowbit(i);
    }
    return ret;
}

void update(int i, int j, int v)
{
    int tmpj;
    while(i<=row)
    {
        tmpj=j;
        while(tmpj<=col)
        {
            c[i][tmpj]+=v;
            tmpj+=lowbit(tmpj);
        }
        i+=lowbit(i);
    }
}

int main()
{
    //IN("poj1195.txt");
    int op,n,x,y,v;
    int l,b,r,t;
    while(~scanf("%d%d",&op,&n))
    {
        col=row=n;
        CL(c,0);
        while(~scanf("%d",&op))
        {
            if(op == 3)break;
            if(op == 1)
            {
                scanf("%d%d%d",&x,&y,&v);
                update(x+1,y+1,v);
            }
            if(2 == op)
            {
                scanf("%d%d%d%d",&l,&b,&r,&t);
                printf("%lld\n",sum(r+1,t+1)+sum(l,b)-sum(l,t+1)-sum(r+1,b));
            }
        }
    }
    return 0;
}