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;}