NC113566 Superhero Battle
Superhero Battle
https://ac.nowcoder.com/acm/problem/113566
Superhero Battle
题目地址:
基本思路:
比较简单的数学+模拟,我们先考虑一下无限循环下去的情况,
很明显只要在一轮循环中不能让HP清零,并且每轮的总和是大于等于零的,那么就会无限循环下去;
否则我们实际上只需要枚举最后一轮怪物被杀的位置,然后直接用剩余的血量去计算一下之前循环的轮数就行了。
算出每个位置的结果取最小就是答案了。
参考代码:
#pragma GCC optimize(2) #pragma GCC optimize(3) #include <bits/stdc++.h> using namespace std; #define IO std::ios::sync_with_stdio(false); cin.tie(0) #define ll long long #define ull unsigned long long #define SZ(x) ((int)(x).size()) #define all(x) (x).begin(), (x).end() #define rep(i, l, r) for (int i = l; i <= r; i++) #define per(i, l, r) for (int i = l; i >= r; i--) #define mset(s, _) memset(s, _, sizeof(s)) #define pb push_back #define pii pair <int, int> #define mp(a, b) make_pair(a, b) #define debug(x) cerr << #x << " = " << x << '\n'; #define pll pair <ll, ll> #define fir first #define sec second #define INF 0x3f3f3f3f #define int ll const int mod = (int)1e9 + 7; void add(int &x, int y) { x += y; if(x >= mod) x -= mod; } void sub(int &x, int y) { x -= y; if(x < 0) x += mod; } inline int read() { int x = 0, neg = 1; char op = getchar(); while (!isdigit(op)) { if (op == '-') neg = -1; op = getchar(); } while (isdigit(op)) { x = 10 * x + op - '0'; op = getchar(); } return neg * x; } inline void print(int x) { if (x < 0) { putchar('-'); x = -x; } if (x >= 10) print(x / 10); putchar(x % 10 + '0'); } const int maxn = 2e5 + 10; int H,n,d[maxn],sum[maxn]; signed main() { IO; cin >> H >> n; rep(i,1,n) { cin >> d[i]; sum[i] = sum[i - 1] + d[i]; } if(sum[n] >= 0){ int res = -1; for(int i = 0 ; i <= n ; i++){ if(H + sum[i] <= 0) { res = i; break; } } cout << res << '\n'; return 0; } int ans = (int)1e18; int tmp = -sum[n]; for(int i = 0 ; i <= n ; i++){ int now = H + sum[i]; if(now <= 0){ ans = min(ans,i); continue; } int need = (now + tmp - 1) / tmp; int res = i + need * n; ans = min(ans,res); } cout << ans << '\n'; return 0; }