The 2011 Rocky Mountain Regional Contest&&Iterated Difference

水题~~~

#include<iostream>
#include<string.h>
#include<stdio.h>
#include<cmath>
#include<algorithm>
using namespace std;
int s[21];
int n;
bool judge()
{
for(int i=0;i<n-1;++i)
if(s[i]!=s[i+1]) return false;
return true;

}
void Change()
{
for(int i=0;i<n;++i)
s[i]=abs(s[i]-s[i+1]);
s
=s[0];
}
int main()
{ int T=0;
while(scanf("%d",&n)!=EOF,n)
{
T++;
for(int i=0;i<n;++i)
scanf("%d",&s[i]);
s
=s[0];
int ans=0;
bool flag(false);
while(ans<=1000&&!flag)
{ Change();
if(!judge()) ans++;
else flag=true;
}
if(flag) printf("Case %d: %d iterations\n",T,ans);
else printf("Case %d: not attained\n",T);
}return 0;
}