Submission #2238541

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Source Code Expand

#include<bits/stdc++.h>
#define F(i,a,b) for(int i=a;i<=(b);++i)
using namespace std;

int n,dia;
int a[101],cnt[101];

int main(){
	scanf("%d",&n);
	F(i,1,n) scanf("%d",a+i), ++cnt[a[i]];
	sort(a+1,a+n+1); dia=a[n];
	if(n==2) {puts("Possible"); return 0;}
	if(n==3) {puts(a[1]==1&&a[2]==2&&a[3]==2?"Possible":"Impossible"); return 0;}
	F(i,1,(dia+1>>1)-1) if(cnt[i]) {puts("Impossible"); return 0;}
	if(dia&1) {if(cnt[dia+1>>1]!=2) {puts("Impossible"); return 0;}}
	else {if(cnt[dia+1>>1]!=1) {puts("Impossible"); return 0;}}
	F(i,(dia+1>>1)+1,dia) if(cnt[i]<=1) {puts("Impossible"); return 0;}
	puts("Possible");
	return 0;
}

Submission Info

Judge Result