HDU 1166 线段树

方法一：>o<
线段树
模板题
代码如下

#include<iostream>#include<cstring>#include<cstdlib>#include<cstdio>using namespace std;const int maxn=500000+10;struct tree{    int lef,rig,mid,sum;}t[maxn];int cas,len,cnt,a;void init(int a,int b,int n){    t[n].lef=a,t[n].rig=b;    t[n].mid=(a+b)/2,t[n].sum=0;    if(a+1==b)        return;    init(a,(a+b)/2,2*n);//左子树---------左闭右开     init((a+b)/2,b,2*n+1);//右子树 }void creat(int pos,int val,int n){    t[n].sum+=val;    if(t[n].lef+1==t[n].rig)        return;    if(pos<t[n].mid)        creat(pos,val,2*n);//左子树     else        creat(pos,val,2*n+1);}int query(int x,int y,int n){    if(t[n].lef==x&&t[n].rig==y)        return t[n].sum;    if(x<t[n].mid){        if(y<=t[n].mid)            return query(x,y,n*2);        else            return query(x,t[n].mid,2*n)+query(t[n].mid,y,2*n+1);    }    else        return query(x,y,2*n+1);}int main(){    scanf("%d",&cas),cnt=1;    while(cas--){        char ord[10];        scanf("%d",&len),init(1,len+1,1);        for(int i=1;i<=len;i++)            scanf("%d",&a),creat(i,a,1);        int x,y;        printf("Case %d:\n",cnt++);        while(scanf("%s",ord)){            if(!strcmp(ord,"End"))                break;            scanf("%d%d",&x,&y);            if(strcmp(ord,"Query")==0)                printf("%d\n",query(x,y+1,1));            else if(strcmp(ord,"Add")==0)                creat(x,y,1);            else if(strcmp(ord,"Sub")==0)                creat(x,-y,1);        }    }    return 0;}