2023蓝桥杯打卡第二天

[一只不愿透露姓名的蒟蒻]

奇数倍数

#include<iostream>
using namespace std;
bool a(long long x) {
    while (x > 0) {
        if (x % 2 == 0)
            return true;
        x /= 10;
    }
    return false;
}
int main() {
    long long x = 2019;
    long long i = 2;
    while (a(x*i)) {
        i++;
    }
    cout << x * i;
    return 0;
}

 求值

#include <iostream>
using namespace std;
int main()
{
 cout<<45360;
  return 0;
}

 求和

#include<iostream>
using namespace std;
#define ll long long
int main()
{
    int a[200000];
    ll s = 0;
    ll n,part=0;
    cin >> n;
    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }
    part = a[0];
    for (int i = 1; i < n; i++) {
        s += part * a[i];
        part += a[i];
    }
    cout << s;
    return 0;
}