游游的水果大礼包
#include <iostream>
#define int long longusing namespace std;
int n, m, a, b;signed main()
{cin>>n>>m>>a>>b;int ret = 0;for(int x = 0; x <= min(n / 2, m); x++) // 枚举 1 号礼包的个数{int y = min(n - x * 2, (m - x) / 2); // 计算 2 号礼包的个数ret = max(ret, a * x + b * y);}cout << ret << endl;return 0;
}
买卖股票的最佳时机（二）
#include <bits/stdc++.h>using namespace std;
int n;
const int N = 1e5+10;
int price[N];int main()
{cin>>n;for(int i = 0;i<n;++i)cin>>price[i];int ans = 0;for(int i = 1;i<n;++i){ans += price[i]-price[i-1]<0 ? 0 : price[i]-price[i-1];}cout<<ans;return 0;
}
倒置字符串
python版简易版
a = input().split()[::-1]
print(" ".join(a))
cpp版
#include <iostream>
#include <string>
#include <algorithm>using namespace std;
string s;int main()
{getline(cin, s);//找到反转的规律就行了//三步上篮reverse(s.begin(), s.end());int left = 0, n = s.size();while (left < n){int right = left;while (right < n && s[right] != ' '){++right;}reverse(s.begin() + left, s.begin() + right);while (right < n && s[right] == ' ')++right;left = right;}cout << s << '\n';return 0;
}
