題目：Farewell Party

程式碼：

#include<bits/stdc++.h>
using namespace std;

#define read(x) scanf("%d",&x)
#define maxn 100000

int n;
vector<int> a[maxn+5];

int col[maxn+5],cnt;

int main() {
	read(n);
	for(int i=1;i<=n;i++) {
		int x;
		read(x);
		a[x].push_back(i);
		if(x>=n) goto
 
 End;
	}
	
	for(int i=0;i<n;i++) {
		if(!a[i].size()) continue;
		
		int lst=n-i;
		if(a[i].size()%lst) goto End;
		
		for(int j=0;j<a[i].size();j++) {
			int x=a[i][j];
			col[a[i][j]]=cnt+j/lst+1;
		}
		
		cnt+=a[i].size()/lst;
	}
	
	printf("Possible\n");
	for(int i=1;i<=n;i++) printf("%d ",col[
 
i]);
	
	return 0;
	
	End:;
	printf("Impossible");
	
	return 0;
}