線段樹入門三道題

//POJ 3264
#include <iostream>  
#include <cstdio>  
#include <cmath>      
using namespace std;  
#define FOR( i , a , b ) for ( int i = a ; i <= b ; ++ i )  
#define Mid ((l+r)>>1)      //括號！  
#define lson rt<<1,l,Mid  
#define rson rt<<1|1,Mid+1,r  

const int maxn= 50005;  
const int inf=0x3f3f3f3f;  
int Max[maxn<<2],Min[maxn<<2];  
int ans1,ans2;  
      
void build(int rt,int l,int r){  
    if(l==r){  
        scanf("%d",&Max[rt]);  
        Min[rt] = Max[rt];  
    }else{  
        build(lson);  
        build(rson);  
        Max[rt] = max( Max[rt<<1], Max[rt<<1|1]);  
        Min[rt] = min( Min[rt<<1], Min[rt<<1|1]);  
    }  
}  
      
void query(int rt,int l,int r,int L,int R){  
    if(L <= l && r <= R){  
        ans1 = max(ans1,Max[rt]);  
        ans2 = min(ans2,Min[rt]);  
    }else{  
        if( L <= Mid)  
            query(lson,L,R);  
        if( R > Mid)  
            query(rson,L,R);  
    }  
}  
     
int main(){  
    int n,m,L,R;  
    while(scanf("%d%d",&n,&m)!=EOF){  
        build(1,1,n);  
        while(m--){  
            ans1 = -inf,ans2 = inf;  
            scanf("%d%d",&L,&R);  
            query(1,1,n,L,R);  
            printf("%d\n", ans1-ans2);  
        }  
    }  
    return 0;  
}  

//HDU1754
#include <iostream>  
#include <cstdio>  
#include <cmath>  
using namespace std;  
#define FOR( i , a , b ) for ( int i = a ; i <= b ; ++ i )  
#define Mid ((l+r)>>1)       
#define lson rt<<1,l,Mid  
#define rson rt<<1|1,Mid+1,r  
      
const int maxn= 200000+5;  
const int inf=0x3f3f3f3f;  
int Max[maxn<<2];  
int ans1,ans2;  
      
void build(int rt,int l,int r){  
    if(l==r)
        scanf("%d",&Max[rt]);  
    else{  
        build(lson);  
        build(rson);  
        Max[rt] = max( Max[rt<<1], Max[rt<<1|1]); 
    }  
}  
void update(int rt,int l,int r,int pos,int num){  
    if(l == r && r == pos)
        Max[rt] = num;  
    else{  
        if( pos <= Mid)  
            update(lson,pos,num);  
        if( pos > Mid)  
            update(rson,pos,num);  
        Max[rt] = max( Max[rt<<1], Max[rt<<1|1]);  
    }  
}  
int query(int rt,int l,int r,int L,int R){  
    if(L <= l && r <= R)
        return Max[rt];  
    else{  
        int tmp = -1;  
        if( L <= Mid)  
            tmp = max(tmp,query(lson,L,R));  
        if( R > Mid)  
            tmp = max(tmp,query(rson,L,R));  
        return tmp;  
    }  
}  
      
int main(){  
    int n,m,L,R;  
    char op;  
    while(scanf("%d%d",&n,&m)!=EOF){  
        build(1,1,n);  
        getchar();  
        while(m--){  
            scanf("%c%d%d%*c",&op,&L,&R);  
            if(op=='Q')  
                printf("%d\n",query(1,1,n,L,R));  
            else  
                update(1,1,n,L,R);  
        }  
    }  
    return 0;  
}  

//HDU1166
#include <iostream>  
#include <cstdio>  
#include <cmath>  
using namespace std;  
#define FOR( i , a , b ) for ( int i = a ; i <= b ; ++ i )  
#define Mid ((l+r)>>1)  
#define lson rt<<1,l,Mid  
#define rson rt<<1|1,Mid+1,r  
const int maxn= 50000+5;  
const int inf=0x3f3f3f3f;  
int sum[maxn<<2];  
int ans1,ans2;  
      
void build(int rt,int l,int r){
    if(l==r)
        scanf("%d",&sum[rt]);  
    else{  
        build(lson);  
        build(rson);  
        sum[rt] = sum[rt<<1] + sum[rt<<1|1];  
    }  
}  

void update(int rt,int l,int r,int pos,int num){  
    if(l == r && r == pos)
        sum[rt] += num;  
    else{  
        if( pos <= Mid)  
            update(lson,pos,num);  
        else          
            update(rson,pos,num);  
        sum[rt] = sum[rt<<1] + sum[rt<<1|1];  
    }  
}  
      
int query(int rt,int l,int r,int L,int R){  
    if(L <= l && r <= R)
        return sum[rt];  
    else{  
        int tmp = 0;  
        if( L <= Mid)  
            tmp += query(lson,L,R);  
        if( R > Mid)  
            tmp += query(rson,L,R);  
        return tmp;  
    }  
}  
      
int main(){  
    int n,m,L,R,t;  
    char op[10];  
    scanf("%d",&t);  
    for(int cas=1;cas<=t;cas++){  
        scanf("%d",&n);  
        build(1,1,n);  
        printf("Case %d:\n",cas);  
        while(scanf("%s",op),op[0]!='E'){  
            scanf("%d%d",&L,&R);  
            if(op[0]=='Q')  
                printf("%d\n", query(1,1,n,L,R));  
            else if(op[0]=='A')  
                update(1,1,n,L,R);  
            else  
                update(1,1,n,L,-R);  
        }  
    }  
    return 0;  
}