HDU4027 Can you answer these queries? 线段树

#include <stdio.h>
#include <string.h>
#include <math.h>
#include <algorithm>
using namespace std;
typedef long long LL;
const int N=1e5+5;
LL a[N<<2];
void build(int rt,int l,int r){
if(l==r){
scanf("%I64d",&a[rt]);
return;
}
int m=(l+r)>>1;
build(rt<<1,l,m);
build(rt<<1|1,m+1,r);
a[rt]=a[rt<<1]+a[rt<<1|1];
}
void modify(int rt,int l,int r,int x,int y){
if(x<=l&&r<=y){
if(a[rt]==r-l+1)return;
}
if(l==r){
a[rt]=sqrt(1.0*a[rt]);
return;
}
int m=(l+r)>>1;
if(x<=m)modify(rt<<1,l,m,x,y);
if(y>m)modify(rt<<1|1,m+1,r,x,y);
a[rt]=a[rt<<1]+a[rt<<1|1];
}
LL ask(int rt,int l,int r,int x,int y){
if(x<=l&&r<=y)return a[rt];
LL ans=0;
int m=(l+r)>>1;
if(x<=m)ans+=ask(rt<<1,l,m,x,y);
if(y>m)ans+=ask(rt<<1|1,m+1,r,x,y);
return ans;
}
int main(){
int n,cas=0;
while(~scanf("%d",&n)){
printf("Case #%d:\n",++cas);
build(1,1,n);
int q;
scanf("%d",&q);
while(q--){
int op,x,y;
scanf("%d%d%d",&op,&x,&y);
if(x>y)swap(x,y);
if(op)printf("%I64d\n",ask(1,1,n,x,y));
else modify(1,1,n,x,y);
}
printf("\n");
}
return 0;
}