南阳 966 选择不相交区间

 #include<stdio.h>#include<string.h>#include<stdlib.h>typedef struct In{int x,y;};In num[1010];int cmp(const void *a,const void *b){In *c=(In *)a;In *d=(In *)b;if(c->y!=d->y) return c->y-d->y; }int main(){int n,m=1,i,j,s;int a,b,t;while(~scanf("%d",&n)){memset(num,0,sizeof(num));for(i=0;i<n;i++){scanf("%d%d",&a,&b);if(a>b){t=a;a=b;b=t;}num[i].x=a;num[i].y=b;}qsort(num,n,sizeof(num[0]),cmp);int max=num[0].y;for(s=i=1;i<n;i++){if(num[i].x>max){s++;max=num[i].y;}}printf("Case %d:\n",m++);printf("%d.\n",s);}return 0;}