BJTU 1623 Problem C. Course Planning

http://acm.bjtu.edu.cn/problem/detail?pid=1623

贪心，关键点是以课程的结束时间为标准排序

#include <stdio.h>
#include <stdlib.h>
struct node
{
    __int64 x,y;
}kk[110000];
int cmp(const void*a,const void*b)
{
    struct node*c=(struct node*)a;
    struct node*d=(struct node*)b;
    if(d->y==c->y)
        return d->x-c->x;
    return d->y-c->y;
}
int main() 
{
    int t,n;
    int nCase;
    int i,f;
    nCase=1;
    scanf("%d",&t);
    while(t--)
    {
        f=0;
        scanf("%d",&n);
        for(i=0;i<n;i++)
            scanf("%I64d%I64d",&kk[i].x,&kk[i].y);
        qsort(kk,n,sizeof(struct node),cmp);
        for(i=0;i<n-1;i++)
            if((kk[i].y-(kk[i].y-kk[i].x)/2-1)<=(kk[i+1].y-(kk[i+1].y-kk[i+1].x)/2-1))
            {
                f=1;
                break;
            }
        if(f)
            printf("Case #%d: No\n",nCase++);
        else 
            printf("Case #%d: Yes\n",nCase++);
    }
    return 0;
}