HDU 3697 Selecting courses 选课（AC代码）贪心

Problem Description
A new Semester is coming and students are troubling for selecting courses. Students select their course on the web course system. There are n courses, the ith course is available during the time interval (Ai,Bi). That means, if you want to select the ith course, you must select it after time Ai and before time Bi. Ai and Bi are all in minutes. A student can only try to select a course every 5 minutes, but he can start trying at any time, and try as many times as he wants. For example, if you start trying to select courses at 5 minutes 21 seconds, then you can make other tries at 10 minutes 21 seconds, 15 minutes 21 seconds,20 minutes 21 seconds… and so on. A student can’t select more than one course at the same time. It may happen that no course is available when a student is making a try to select a course

You are to find the maximum number of courses that a student can select.

Input
There are no more than 100 test cases.

The first line of each test case contains an integer N. N is the number of courses (0

#include <iostream>#include<algorithm>#include<cstring>using namespace std; /* run this program using the console pauser or add your own getch, system("pause") or input loop */int map[1000];int main(int argc, char** argv) {    int t;    int a[5];    memset(map,0,sizeof (map));    memset(a,0,sizeof(a));    cin>>t;    int n;    n=t;    int max=0;    while(t){        t--;        int x,y;        max=(max<y)?y:max;        cin>>x>>y;        for(int i=x-1;i<y;i++){            map[i]=1;        }    }    for(int i=0;i<5;i++){        for(int j=0;j<max;j+=5)        {            if(map[j]==1){                a[i]+=1;            }        }    }    sort(a,a+5);    cout<<a[4];    return 0;}