CF1607C Minimum Extraction

https://www.luogu.com.cn/problem/CF1607C
找规律做的

#include<bits/stdc++.h>
#define int long long
using namespace std;
const int N = 2e5 + 10;
int a[N];
signed main()
{
    int t; cin >> t;while (t -- ){
    int n; scanf("%lld", &n);for (int i = 1; i <= n; i ++ ){
    scanf("%lld", &a[i]);}if (n == 1){
    printf("%lld\n", a[1]);continue;}sort (a + 1, a + 1 + n);int maxn = -1e9 - 7;a[0] = 0;for (int i = 1; i <= n; i ++ ){
    maxn = max(maxn, a[i] - a[i - 1]);}printf("%lld\n", maxn);}return 0;
}