菜3：贪心法--选择不相交区间

原理不再讲了，在紫皮书232页。

#include<iostream>
#include<stdio.h>
#include <algorithm>
using namespace std;
struct time
{
    int start,end;
};
int cmp(struct time a, struct time b)
{
    return a.end < b.end;
}
int main()
{
    int n;
    while(scanf("%d",&n)!=EOF && n!=0)
    {
        struct time time_table[1000];
        int cnt = 0;
        for ( int i = 0; i < n; i++)
        {
            scanf("%d %d",&time_table[i].start, &time_table[i].end);
        }
        sort(time_table,time_table+n,cmp);
        int bench = time_table[0].end;
        for ( int i = 1; i < n; i++ )
        {
            if ( time_table[i].start >= bench )
            {
                cnt ++ ;
                bench = time_table[i].end;
            }
        }
        printf("%d\n", cnt);
    }

}