codeforces- 973-div2----补题

1、求最小时间

思路：简单的模拟 + 木桶效应

#include<iostream>
#include<algorithm>
using namespace std;
typedef long long ll;
int dx[] = { 0,1,0,-1 };
int dy[] = { 1,0,-1,0 };
const ll N = 2e5 + 5;
const ll mod = 1e9 + 7;
ll a[N];
void solve()
{
    ll n, x, y;
    cin >> n >> x >> y;
    ll ans = 0;
    ll d = min(x, y);
    ans = n / d;
    if (n % d)
        ans++;
    cout << ans << "\n";
}
int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);
    int t = 1; cin >> t;
    while (t--)
    {
        solve();
    }
}

2.Battle for Survive

#include<iostream>
using namespace std;
const int N = 200010;
typedef long long ll;
ll a[N];
void solve()
{
	ll n;
	cin >> n;
	ll ans = 0;
	for (int i = 1; i <= n; i++) cin >> a[i];
	for (int i = 1; i < n - 1; i++)
	{
		ans += a[i];
	}
	ll res = a[n - 1] - ans;
	cout << a[n] - res << endl;
}
int main()
{
	int t;
	cin >> t;
	while (t--)
	{
		solve();
	}
	return 0;
}