Poj 3264 balanced lineup [Line Segment tree, water]

Returns the difference of the greatest value in the interval.

Two Queries are used. The query time is 3 S +... so slow and fast.

#include<cstdio>#include<algorithm>#include<cstring>using namespace std;#define lson    l,m,rt<<1#define rson    m+1,r,rt<<1|1const int MM=1000005;const int maxn=50005;int MAX[maxn<<2],MIN[maxn<<2];void build(int l,int r,int rt){    if(l==r){        scanf("%d",&MAX[rt]);        MIN[rt]=MAX[rt];        return ;    }    int m=(l+r)>>1;    build(lson);    build(rson);    MAX[rt]=max(MAX[rt<<1],MAX[rt<<1|1]);    MIN[rt]=min(MIN[rt<<1],MIN[rt<<1|1]);}int query1(int L,int R,int l,int r,int rt){    if(L<=l&&R>=r){        return MAX[rt];    }    int m=(l+r)>>1;    int ret=0;    if(L<=m) ret=max(ret,query1(L,R,lson));    if(R>m) ret=max(ret,query1(L,R,rson));    return ret;}int query2(int L,int R,int l,int r,int rt){    if(L<=l&&R>=r){        return MIN[rt];    }    int m=(l+r)>>1;    int ret=MM;    if(L<=m) ret=min(ret,query2(L,R,lson));    if(R>m) ret=min(ret,query2(L,R,rson));    return ret;}int main() {    int N,Q;    while(~scanf("%d%d",&N,&Q)) {        build(1,N,1);        while(Q--){            int a,b;            scanf("%d%d",&a,&b);            printf("%d\n",query1(a,b,1,N,1)-query2(a,b,1,N,1));        }    }    return 0;}