区间重合判断

#include <iostream>
#include <algorithm>

struct Entry
{
    int x;
    int y;
};

bool cmp(const Entry &a, const Entry &b)
{
    return a.x < b.x || (a.x == b.x && a.y <= b.y);
}

int binsearch(Entry* a,int low,int high, const int value)
{
    int mid;
    while (low <= high)
    {
        mid = low + (high - low)/2;
        Entry& tmp = a[mid];
        if (tmp.x <= value && value <= tmp.y) return mid;
        else if (value < tmp.x) high = mid -1;
        else low =  high + 1;
    }
    return -1;
}
const int MAXN = 256;

int main()
{
    Entry arr[MAXN] = {0},brr[MAXN] = {0};
    int n;
    scanf("%d",&n);
    for (int i = 0; i < n; ++i)
        scanf("%d %d",&(arr[i].x),&(arr[i].y));
    std::sort(arr,arr+n,cmp);
    int x,y;
    scanf("%d %d",&x,&y);
    //[a,b],[c,d],a <= c
    //(1) [a,b] U [c,d] = [a,b] ,a <= c && d <= b
    //(2) [a,b] 交 [c,d] = 0 , b < c
    //(3) [a,b] U [c,d] = [a,d]
    int cnt = 0;
    brr[cnt++] = arr[0];
    for (int i = 1; i < n; ++i)
    {
       if (brr[cnt-1].y < arr[i].x) // [a,b] N [c,d] = 0 ,b < c
       {
         brr[cnt++] = arr[i];
       }
       else if (arr[i].x <= brr[cnt-1].y && brr[cnt-1].y <= arr[i].y)
       {
            brr[cnt-1].y = arr[i].y;
       }
       else if(brr[cnt-1].y >= arr[i].y)
       {
       }
    }
    /*for (int i = 0; i < cnt; ++i)
    {
        printf("(%d,%d),",brr[i].x,brr[i].y);
    }
    */
    int xpos = binsearch(brr,0,cnt-1,x);
    int ypos = binsearch(brr,0,cnt-1,y);
    if (xpos != -1 && ypos != -1 && xpos == ypos)
    {
        printf("suc\n");
    }
    else
    {
        printf("fail\n");
    }
}