hdu 1166敌兵布阵(线段树或者树状数组)
http://acm.hdu.edu.cn/showproblem.php?pid=1166
不懂得可以看刘汝佳训练指南P194
//树状数组版：#include <iostream>#include <cstdio> #include <cstring>using namespace std;int n,s[50005];int LowBit(int x){ return x&-x; }void Add(int x,int d){ while(x<=n) { s[x]+=d; x+=LowBit(x);}}int Sum(int x){ int ans=0; while(x>0) { ans+=s[x]; x-=LowBit(x); } return ans;}int main(int argc, char *argv[]){ int t,i,d,k=1; char a[10]; scanf("%d",&t); while(t--!=0) { printf("Case %d:\n",k++); scanf("%d",&n); memset(s,0,sizeof(s)); for(i=1;i<=n;i++) { scanf("%d",&d); Add(i,d); } while(scanf("%s",a)) { if(a[0]=='E') break; scanf("%d%d",&i,&d); if(a[0]=='Q') printf("%d\n",Sum(d)-Sum(i-1)); else if(a[0]=='A') Add(i,d); else if(a[0]=='S') Add(i,-d); } } return 0;}