线段覆盖

http://codevs.cn/problem/1214/
右端点排序。注意左右端点大小，数值有可能是负的。

#include<iostream>
using namespace std;
struct MyStruct
{
    int a;
    int b;
}jiegouti[200];
int main()
{
    int n;
    cin >> n;
    int a, b;
    for (int i = 0; i < n; i++)
    {
        cin >> a>>b;
        if (a>b)
        {
            jiegouti[i].b = a;
            jiegouti[i].a = b;
        }
        else
        {
            jiegouti[i].b = b;
            jiegouti[i].a = a;
        }
    }
    for (int i = 0; i < n-1; i++)
    {
        for (int j = i + 1; j < n; j++)
        {
            if (jiegouti[i].b>jiegouti[j].b)
            {
                swap(jiegouti[i],jiegouti[j]);
            }
        }
    }
    int num = 0;
    int temp=-22222222;
    for (int i = 0; i < n; i++)
    {
        if (jiegouti[i].a>=temp)
        {
            temp=jiegouti[i].b;
            num++;
        }
    }
    cout << num << endl;
    system("pause");
    return 0;
}