acm 练习

sdnuacm 1108

poj 2575

Description

A sequence of n > 0 integers is called a happy luguan if the absolute values of the difference between successive elements take on all the values 1 through n-1. For instance,

1 4 2 3

is a happy luguan, because the absolutes differences are 3, 2, and 1 respectively. The definition implies that any sequence of a single integer is a happy luguan. You are to write a program to determine whether or not each of a number of sequences is a happy luguan.

Input

Each line of input contains an integer n <= 3000 followed by n integers representing the sequence.

Output

For each line of input, generate a line of output saying "Happy luguan" or "Not happy luguan".

Sample Input

4 1 4 2 3
5 1 4 2 -1 6

Sample Output

Happy luguan
Not happy luguan

很简单，判断数列中的相邻的两个数的差的绝对值是否是1，2····n-1。

我们可以用所做的差做一个数组的下标，并将其设为一固定的值最后检查一下就可以啦

以下为代码：

#include <stdio.h>
#include <string.h>
#include <iostream>
#include <vector>
#include <iterator>
#include <cmath>
#include <algorithm>
#include <cstdio>
#include <cmath>
#include <cstring>
using namespace std;
int di[3002];
int main()
{
    int n,x,y;
    int ch;
    while(scanf("%d",&n)!=EOF)
    {
        ch=1;
        memset(di,0,sizeof(di));
        if(n==1)
        {
            scanf("%d",&x);
            printf("Happy luguan\n");
            continue;
        }
        scanf("%d",&x);
        for(int i=1; i<n; i++)
        {
            scanf("%d",&y);
            int te=abs(y-x);
            di[te]=1;
            x=y;
        }
        int j;
        for( j=1; j<n; j++)
        {
            if(di[j]==0)
                ch=0;
        }
        if(ch==1)
        {
            printf("Happy luguan\n");
        }
        else
            printf("Not happy luguan\n");
    }
}