活动安排问题-2 (51nod)

水，等同于去吃饭，进进出出，问你餐厅里最多同时有几个人一样

#include <cstdio>#include <cstring>#include <algorithm>using  namespace std;int read(){int ret=0;char ch=getchar();while(ch<'0'||ch>'9') ch=getchar();for(;ch>='0'&&ch<='9';ch=getchar()) ret=ret*10+ch-'0';return ret;}struct t{    int a,b;}p[20005];bool cmp(t x,t y){if(x.a!=y.a)return x.a<y.a;return x.b<y.b;}int main(){    int n=read()<<1;    for(int i=1;i<=n;i++)        p[i].a=read(),p[i].b=i&1?1:-1;    sort(p+1,p+n+1,cmp);    int ans=0,cur=0;    for(int i=1;i<=n;i++)    {        cur+=p[i].b;        ans=max(cur,ans);    }    printf("%d\n",ans);}