bzoj1651: [Usaco2006 Feb]Stall Reservations 专用牛棚

链接：http://www.lydsy.com/JudgeOnline/problem.php?id=1651

题意：中文题。。

分析：裸的差分应用。。

代码：

#include<map>
#include<set>
#include<cmath>
#include<queue>
#include<math.h>
#include<cstdio>
#include<vector>
#include<string>
#include<cstring>
#include<iostream>
#include<algorithm>
#pragma comment(linker, "/STACK:102400000,102400000")
using namespace std;
const int N=1000010;
const int MAX=151;
const int MOD=1000007;
const int MOD1=100000007;
const int MOD2=100000009;
const int INF=2100000000;
const double EPS=0.00000001;
typedef long long ll;
typedef unsigned long long ull;
int read()
{
    int x=0,f=1;char ch=getchar();
    while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
    while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
    return x*f;
}
int f[N];
int main()
{
    int a,b,i,n,ans=0;
    scanf("%d", &n);
    memset(f,0,sizeof(f));
    while (n--) {
        scanf("%d%d", &a, &b);
        f[a]++;f[b+1]--;
    }
    for (i=1;i<=1000000;i++) {
        f[i]+=f[i-1];ans=max(ans,f[i]);
    }
    printf("%d\n", ans);
    return 0;
}