題目：

I Hate It

5 61 2 3 4 5Q 1 5U 3 6Q 3 4Q 4 5U 2 9Q 1 5 Sample Output
5659HintHuge input,the C function scanf() will work better than cin
代碼：
#include<iostream>#include<cstring>#include<cstdio>#include<cstdlib>#include<ctype.h>    //tower()#include<set>  #include<map>  #include<iomanip>// cout<<setprecision(1)<<fixed<<a;#include<vector>   #include<time.h>  #include<assert.h>  //assert#include<cmath>	#include<algorithm>#include<bitset>#include<limits.h>#include<stack>#include<queue>using namespace std;const int maxn=200010;const int inf=0x7fffffff;/*線段樹單點(diǎn)更新*/#define lson l,mid,rt<<1#define rson mid+1,r,rt<<1|1int n,m,stree[maxn<<2];void build(int l,int r,int rt){//葉節(jié)點(diǎn)從l到r，樹根為rt	if(l==r){		scanf("%d",&stree[rt]);///stree[rt]=a[l];		return;	}	int mid=(l+r)>>1;	build(lson);//自左向右讀入a[]中數(shù)據(jù) 	build(rson);	stree[rt]=max(stree[rt<<1],stree[rt<<1|1]); }void update(int x,int v,int l,int r,int rt){//線段樹（樹根為rt，對應(yīng)區(qū)間為[l,r]）中x結(jié)點(diǎn)更新為v 	if(l==r){		stree[rt]=v;		return;	}	int mid=(l+r)>>1;	if(x<=mid) update(x,v,lson);	if(x>mid) update(x,v,rson);	stree[rt]=max(stree[rt<<1],stree[rt<<1|1]);}int query(int a,int b,int l,int r,int rt){//查詢線段樹（樹根為rt，對應(yīng)區(qū)間為[l,r]）中子區(qū)間[a,b]的最大值 	if(a<=l&&b>=r) return stree[rt];	int ans=-inf;	int mid=(l+r)>>1;	if(a<=mid) ans=max(query(a,b,lson),ans);	if(b>mid) ans=max(query(a,b,rson),ans);	return ans;}int main(){//1560MS	4696K	while(scanf("%d%d",&n,&m)==2){		memset(stree,0,sizeof(stree));		build(1,n,1);		char s[5];		int p,q;		while(m--){			scanf("%s%d%d",s,&p,&q);			if(s[0]=='U') update(p,q,1,n,1);			else printf("%d/n",query(p,q,1,n,1));		}	}	return 0;}