http://www.cnblogs.com/chinazhangjie/archive/2010/11/23/1885330.html 贪心分析。
#include <iostream>
#include <cstdio>
#include <algorithm>
using namespace std;
struct node
{
int st, en;
} p[112];
bool cmp(node a, node b)
{
return a.en < b.en;
}
int main()
{
int n;
while(scanf("%d", &n)!=EOF && n)
{
for(int i = 0; i < n; i++)
scanf("%d%d", &p[i].st, &p[i].en);
sort(p, p+n, cmp);
int g = 0;
int cnt = 0;
for(int i = 1; i < n; i++)
{
if(p[i].st>=p[g].en)
{
g = i;
cnt++;
}
}
printf("%d\n", cnt+1);
}
}