前面填空参考https://blog.csdn.net/2301_76891851/article/details/143448411
后面大题code：
停车场停车
#include <bits/stdc++.h>
#define int long long
using namespace std;
int tmp;
signed main()
{int n;cin>>n;if(n<15)cout<<"0";else{cout<<(n/15)*2;}return 0;
}
非零数减一
#include <bits/stdc++.h>
#define int long long
using namespace std;
int tmp;
signed main()
{char c='0';int n;cin>>n;string a=to_string(n);for(int i=0;i<a.length();i++){if(c<a[i])c=a[i];}cout<<c;return 0;
}
减法运算
#include <bits/stdc++.h>
#define int long long
using namespace std;
int tmp;
signed main()
{string res1="",res2="";string a;cin>>a;int index=a.find("-");for(int i=0;i<index;i++)res1+=a[i];for(int i=index+1;i<a.length();i++)res2+=a[i];int cnt1=stoll(res1);int cnt2=stoll(res2);cout<<cnt1-cnt2;return 0;
}
间隔为k
#include <bits/stdc++.h>
#define int long long
using namespace std;
int mx=0;
int arr[100010];signed main()
{int n;cin>>n;for(int i=1;i<=n;i++)cin>>arr[i];int k;cin>>k;int r=n-2*k-2;for(int i=1;i<=r;i++){int sum=0;//sum要在这里进行初始化 for(int j=i;j<=i+2*k-2;j+=2){sum+=arr[j];}if(sum>mx){mx=max(mx,sum);}}cout<<mx;return 0;
}
钩子
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;int main() {int n;cin >> n;vector<int> a(n);for (int i = 0; i < n; i++) {cin >> a[i];}if (n < 3) {cout << 0 << endl;return 0;}vector<int> decreasing(n, 1);vector<int> increasing(n, 1);// 计算每个位置之前的最长递减子序列for (int i = 0; i < n; i++) {for (int j = 0; j < i; j++) {if (a[j] > a[i]) {decreasing[i] = max(decreasing[i], decreasing[j] + 1);}}}// 计算每个位置之后的最长递增子序列for (int i = n - 1; i >= 0; i--) {for (int j = i + 1; j < n; j++) {if (a[j] > a[i]) {increasing[i] = max(increasing[i], increasing[j] + 1);}}}int max_length = 0;for (int i = 0; i < n; i++) {if (decreasing[i] > 1 && increasing[i] > 1) {max_length = max(max_length, decreasing[i] + increasing[i] - 1);}}cout << max_length << endl;return 0;
}
