SCU - 1997 Jolly Jumpers
A sequence of n > 0 integers is called a jolly jumper 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 jolly jumper, because the absolutes differences are 3, 2, and 1 respectively. The definition implies that any sequence of a single integer is a jolly jumper. You are to write a program to determine whether or not each of a number of sequences is a jolly jumper.
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 “Jolly” or “Not jolly”.
Sample Input
4 1 4 2 3
5 1 4 2 -1 6
Sample Output
Jolly
Not jolly
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题意:
给一个长为n的序列,若序列任意相邻两个数差的绝对值为1,2,…,n-1之间的所有值,则输出“Jolly”,否则输出“Not jolly”。
思路:
- 用数组a存储长为n的序列,数组b为任意两个数之间差的绝对值;
- 将数组b从小到大排列(用sort函数);
- 判断数组b中的值是否与1,2,…,n-1一一对应,若对应,则输出“Jolly”,否则输出“Not jolly”。
代码如下:
#include <iostream>
#include <math.h>
#include <algorithm>
using namespace std;
int main()
{
int n;
while(cin>>n)
{
int i,a[3005],b[3005];
for(i=0;i<n;++i)
{
cin>>a[i];
}
int j=0;
for(i=0;i<n-1;++i)
{
b[j]=fabs(a[i]-a[i+1]);//存绝对值
j++;
}
sort(b,b+j);
int k=0;
bool flag=true;
for(i=1;i<n;++i)
{
if(b[k]!=i)
{
flag=false;
break;
}
else
k++;
}
if(flag)
cout<<"Jolly";
else
cout<<"Not jolly";
cout<<endl;
}
return 0;
}
测试链接.