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4956. 冶炼金属
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题意
第十四届蓝桥杯省赛C++B组
略
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思路
二分最小值和最大值即可
最小值:check的时候,如果大于b了就不行
最大值:check的时候,如果小于b了就不行 -
代码
/* * @Author: NEFU AB-IN * @Date: 2023-04-18 20:00:24 * @FilePath: \Acwing\4956\4956.cpp * @LastEditTime: 2023-04-18 20:00:35 */ #include <bits/stdc++.h> using namespace std; #define int long long #undef int #define SZ(X) ((int)(X).size()) #define ALL(X) (X).begin(), (X).end() #define IOS \ ios::sync_with_stdio(false); \ cin.tie(nullptr); \ cout.tie(nullptr) #define DEBUG(X) cout << #X << ": " << X << '\n' typedef pair<int, int> PII; const int N = 1e4 + 10, INF = 0x3f3f3f3f; int a[N], b[N]; int n; bool check(int x, int flag) { for (int i = 1; i <= n; ++i) { if (flag == 1 && a[i] / x > b[i]) return false; if (flag == 2 && a[i] / x < b[i]) return false; } return true; } signed main() { IOS; cin >> n; for (int i = 1; i <= n; ++i) { cin >> a[i] >> b[i]; } // 最小值 int l = 1, r = INF; while (l < r) { int mid = l + r >> 1; if (check(mid, 1)) r = mid; else l = mid + 1; } cout << r << " "; // 最大值 l = 1; r = INF; while (l < r) { int mid = l + r + 1 >> 1; if (check(mid, 2)) l = mid; else r = mid - 1; } cout << r; return 0; }