蓝桥杯C++组部分填空题

P1508 - [蓝桥杯2020初赛] 门牌制作 - New Online Judge

#include<bits/stdc++.h>
using namespace std;int main()
{int res = 0;for(int i = 1; i <= 2020; i++){int num = i;while(num){if(num % 10 == 2) res++;num/=10;}}cout<<res;return 0;
}

624

P1509 - [蓝桥杯2020初赛] 既约分数 - New Online Judge

#include<bits/stdc++.h>using namespace std;
int gcd(int x,int y)
{//辗转相除/*x / y == n ... my / m == n2 ... m2*/ while(x % y){int z = x % y;x = y;y = z;}//别忘记return yreturn y; 
}
int main()
{long long res = 0;for(int i = 1;i <= 2020; i++){for(int j = 1; j<= 2020; j++){if(gcd(i,j)==1) res++; }}cout<<res;return 0;
}

2481215

P1514 - [蓝桥杯2020初赛] 约数个数 - New Online Judge

#include<iostream>
#include<cstring>
#include<algorithm>using namespace std;int main()
{int n = 1200000;long long res = 0;for(int i = 1;i <= n; i++){if(n % i == 0) res++;}cout<<res;return 0;
}

96

P1550 - [蓝桥杯2021初赛] 卡片 - New Online Judge

#include<iostream>
#include<cstring>
#include<algorithm>using namespace std;int main()
{int a[10];for(int i = 0;i<=9;i++)a[i] = 2021;// bool flag = false;int i = 1;//从1开始while(!flag){int num = i;while(num){int k = num % 10;if(a[k]<=0) {flag = true;}a[k]--;num /= 10;}if(flag){cout<<i - 1;//当前不能拼接，返回上一个可以拼接的数字 break; } i++;}return 0;
}

3181