J - Straight Master Gym - 101775J 差分

题意：纸牌顺子：连续的3张或连续的4张或连续的5张为顺子。手中的牌共有n个数字，每个数字是a[i]个，能不能把手中所有的牌都是属于顺子。

• 1 ≤ T ≤ 100.
• 1 ≤ N ≤ 2 × 10.
• 0 ≤ a ≤ 10.
• .

#include <bits/stdc++.h>
#define rep(i, a, b) for(int i = a; i <= b; i++)
#define ll long long
using namespace std;
const int maxn = 1e6;
const ll INF = 0x3f3f3f3f3f3f3f;

ll a[maxn], b[maxn];

int main(){
    ios::sync_with_stdio(false);
    int t, k = 0;
    cin >> t;
    while(t--){
        int n; cin >> n;
        rep(i, 1, n){
            cin >> a[i];
            b[i] = a[i] - a[i-1];
        }
        b[n+1] = -a[n];
        int tot = 0;
        rep(i, 1, n+1){
            if(b[i] >= 0) tot += b[i];
            else {tot = 1; break;}
            int pos = i+3;
            if(pos > n+1) break;
            if(b[pos] < 0) tot += b[pos], b[pos] = 0;
            if(tot < 0) break;
        }
        printf("Case #%d: ", ++k);
        if(tot) printf("No\n");
        else printf("Yes\n");
    }
    return 0;
}