poj 3988 Selecting courses

poj 3988 Selecting courses

#include<iostream>#include<cstdio>#include<cstdlib>#include<cstring>#include<algorithm>using namespace std;const int MAXN=400;struct node{    int s,t;}a[MAXN];int N;bool v[MAXN];void Solve(){    int now,Minj,ans=0;    for (int i=0;i<5;i++)    {        memset(v,0,sizeof(v));        now=0;        for (int st=i;st<=1000;st+=5)        { Minj=0; for (int k=1;k<=N;k++)     if (!v[k] && a[k].s<=st && st< a[k].t)         if (!Minj || a[Minj].t>a[k].t) Minj=k;     if (Minj)     {         v[Minj]=1;         now++;     }        }        if (now>ans) ans=now;    }    printf("%dn",ans);}int main(){    while (scanf("%d",&N),N)    {        for (int i=1;i<=N;i++)   scanf("%d %d",&a[i].s,&a[i].t);        Solve();    }}