SPOJ GSS5 Can you answer these queries V (line segment tree)

The trouble with GSS3 lies in determining the intersection of two intervals.

There are three scenarios.

1. x1 y1 x2 y2

In this case, the right maximum of x1 y1 + sum [y1 x2] + x2 y2 is the largest

2. x1 x2 y2 y1 is actually when y1 = y2

Either interval between x2-y2

Either the range header is between x1 x2 and the end is between x2 y2

3. x1 x2 y1 y2.

This case and 2 Compare this time the x1-y2 interval is divided into three sections. You only need to enumerate the intervals in which the beginning and end are located.

Note that. It is possible that x2 = y1

Therefore, pay attention to the boundary during comparison.

#include 
 
  #include 
  
   #include #include 
   
    #define maxn 11111#define lson num<<1,s,mid#define rson num<<1|1,mid+1,eusing namespace std;int tre[maxn<<2];int lef[maxn<<2];int rig[maxn<<2];int sum[maxn<<2];void pushup(int num){    sum[num]=sum[num<<1]+sum[num<<1|1];    lef[num]=max(lef[num<<1],sum[num<<1]+lef[num<<1|1]);    rig[num]=max(rig[num<<1|1],sum[num<<1|1]+rig[num<<1]);    tre[num]=max(tre[num<<1],max(tre[num<<1|1],lef[num<<1|1]+rig[num<<1]));}void build(int num,int s,int e){    if(s==e)    {        scanf("%d",&tre[num]);        lef[num]=rig[num]=sum[num]=tre[num];        return;    }    int mid=(s+e)>>1;    build(lson);    build(rson);    pushup(num);}int Q_sum(int num,int s,int e,int l,int r){    if(l>r)return 0;    if(l<=s && r>=e)    {        return sum[num];    }    int mid=(s+e)>>1;    if(r<=mid)return Q_sum(lson,l,r);    else if(l>mid)return Q_sum(rson,l,r);    else    {        return Q_sum(lson,l,mid)+Q_sum(rson,mid+1,r);    }}int Q_L(int num,int s,int e,int l,int r){    if(l>r)return 0;    if(l<=s && r>=e)    {        return lef[num];    }    int mid=(s+e)>>1;    if(r<=mid)return Q_L(lson,l,r);    else if(l>mid)return Q_L(rson,l,r);    else return max(Q_L(lson,l,mid),max(Q_sum(lson,l,mid),Q_sum(lson,l,mid)+Q_L(rson,mid+1,r)));}int Q_R(int num,int s,int e,int l,int r){    if(l>r)return 0;    if(l<=s && r>=e)    {        return rig[num];    }    int mid=(s+e)>>1;    if(r<=mid)return Q_R(lson,l,r);    else if(l>mid)return Q_R(rson,l,r);    else return max(Q_R(rson,mid+1,r),max(Q_sum(rson,mid+1,r),Q_sum(rson,mid+1,r)+Q_R(lson,l,mid)));}int query(int num,int s,int e,int l,int r){    if(l>r)return 0;    if(l<=s && r>=e)    {        return tre[num];    }    int mid=(s+e)>>1;    if(r<=mid)return query(lson,l,r);    else if(l>mid)return query(rson,l,r);    else    {        return max(Q_L(rson,mid+1,r)+Q_R(lson,l,mid),max(query(lson,l,mid),query(rson,mid+1,r)));    }}int main(){    int T;    scanf("%d",&T);    while(T--)    {        int n;        scanf("%d",&n);        build(1,1,n);        int m;        scanf("%d",&m);        while(m--)        {            int x1,x2,y1,y2;            scanf("%d%d%d%d",&x1,&y1,&x2,&y2);            if(x2>y1)            {                printf("%d\n",Q_R(1,1,n,x1,y1)+Q_sum(1,1,n,y1+1,x2-1)+Q_L(1,1,n,x2,y2));            }            else if(y1==y2)            {                printf("%d\n",max(query(1,1,n,x2,y2),Q_L(1,1,n,x2,y2)+Q_R(1,1,n,x1,x2-1)));            }            else            {                printf("%d\n",max(Q_R(1,1,n,x1,x2-1)+Q_L(1,1,n,x2,y1),max(Q_R(1,1,n,x1,x2-1)+Q_L(1,1,n,y1+1,y2)+Q_sum(1,1,n,x2,y1),max(Q_R(1,1,n,x2,y1)+Q_L(1,1,n,y1+1,y2),query(1,1,n,x2,y1)))));            }        }    }    return 0;}/*36 3 -2 1 -4 5 221 3 4 5*/