hdu 1754 I Hate It (单点更新，区间最值）

来源：互联网发布：淘宝卖家修改快递单号编辑：程序博客网时间：2024/05/22 06:47

#include<iostream>#include<cstdio>#include<algorithm>#include<cmath>using namespace std;#define lson i<<1,l,m#define rson i<<1|1,m+1,r#define maxn 200005int Max[maxn<<2];void PushUp(int i){    Max[i]=max(Max[i<<1],Max[i<<1|1]);}void build(int i,int l,int r){    if(l==r) {scanf("%d",&Max[i]);getchar();return;}    int m=(l+r)>>1;    build(lson);    build(rson);    PushUp(i);}void update(int a,int b,int i,int l,int r){    if(l==r) {Max[i]=b;return;}    int m=(l+r)>>1;    if(a<=m) update(a,b,lson);    else update(a,b,rson);    PushUp(i);}int query(int L,int R,int i,int l,int r){    if(L<=l&&r<=R) return Max[i];    int m=(l+r)>>1;    int ans=0;    if(L<=m) ans=max(ans,query(L,R,lson));    if(R>m) ans=max(ans,query(L,R,rson));    return ans;}int main(){    int m,n;    while(scanf("%d%d",&n,&m)!=EOF)    {            build(1,1,n);            char s;            while(m--)            {                int a,b;                scanf("%c%d%d",&s,&a,&b);                getchar();                if(s=='Q') printf("%d\n",query(a,b,1,1,n));                else if(s=='U') update(a,b,1,1,n);            }    }    return 0;}

0 0