题解

#include <bits/stdc++.h>
using namespace std;
int A[100010];
int main(){
    int n;
    cin >> n;
    for(int i = 1;i <= n;i++){
    	cin >> A[i];
    }
    sort(A + 1,A + n + 1);
    if((A[n] - A[1]) % 3 == 0){
    	cout << A[n] - A[1];
        return 0;
    }
    int maxx[13] = {-1,-1,-1},minn[13] = {1001,1001,1001};
    for(int i = 1;i <= n;i++){
    	int x = A[i] % 3;
        if(A[i] > maxx[x]){
            maxx[x]=A[i];
        } 
        if(A[i] < minn[x]){
            minn[x] = A[i];
        } 
    }
    int ans = 0;
    for(int i = 0;i <= 2;i++){
    	if(maxx[i] - minn[i] > ans){
            ans = maxx[i] - minn[i];
        } 
    }
    cout << ans << endl;
	return 0;
}