输入:第一行整数n,第二行n个整数
输出:两两组合可以被7整除的个数
#include <stdio.h>
long long mergeinteger1(int a, int b)
{
long long sum = 0;
//if (b >= 0)
int mid = b;
sum += a * 10;
/*while (mid /= 10)
{
sum *= 10;
}*/
for (; mid /= 10; sum *= 10);
sum += b;
return sum;
}
int main()
{
int n = 0;
int i = 0;
int j = 0;
long long sum1 = 0;
long long sum2 = 0;
long long mid;
int count = 0;
int A[100000] = { 0 };
scanf_s("%d", &n);
for (i = 0; i<n; i++)
{
scanf_s("%d", &A[i]);
}
for (i = 0; i<n; i++)
for (j = i + 1; j<n; j++)
{
printf("%lld ", mergeinteger1(A[i], A[j]));
printf("%lld ", mergeinteger1(A[j], A[i]));
if (mergeinteger1(A[i], A[j]) % 7 == 0)
count++;
if (mergeinteger1(A[j], A[i]) % 7 == 0)
count++;
}
printf("%d\n", count);
}