poj 2620 Minimal coverage

poj 2620 Minimal coverage

#include<stdio.h>#include<string.h>#include<algorithm>using namespace std;struct dian{    int s;    int e;    int l;}d[100015],d1[100015];bool cmp(struct dian a,struct dian b){    if(a.s==b.s)        return a.e<b.e;    return a.s<b.s;}int main(){    int t,i,j;    int st,en;    int m,flag;    int max1;    int x,y;    int sum,flag1;    int k;    while(scanf("%d",&m)!=EOF)    {        flag=0;        sum=0;        k=0;        while(1)        { scanf("%d%d",&x,&y); if(x==0&&y==0)     break; d[k].s=x; d[k].e=y; d[k].l=y-x; k++;        }        sort(d,d+k,cmp);        st=0;        int kk=0;        int pos=100005;        int jl=0;        while(st<m&&flag==0)        { max1=-100005; pos=100005; for(i=kk;i<k;i++) {     if(d[i].s<=st&&d[i].e>=st)     {         if(d[i].e>max1) max1=d[i].e,pos=i;         kk++;     }     else if(d[i].s>st)         break; } if(pos==100005) {     flag=1;     break; } st=max1; sum++; d1[jl].s=d[pos].s; d1[jl++].e=d[pos].e;        }        if(flag==0)        {        printf("%dn",sum);          for(i=0;i<jl;i++)          { printf("%d %dn",d1[i].s,d1[i].e);          }        }        if(flag==1) printf("No solutionn");    }}