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#2
林月儿2018-10-19 22:50
应该是轮询每个位上出现1的次数再加和吧
 程序代码：#include <iostream> #include <cstdio> using namespace std; int main() { int n; scanf("%d", &n); int sum = 0; int k; for(int i = 1; k = n / i;i *= 10) { cout<<k<<":"<<i<<":"<<sum<<endl; int sum2=sum; sum += k/10 * i; int tem = k % 10; if(tem > 1) sum += i; if(tem == 1) sum += n - k*i + 1; cout<<"after:"<<i<<":sum+"<<sum-sum2<<endl; } printf("%d\n", sum); return 0; } 只有本站会员才能查看附件，请 登录 |
输入n是书的页数，然后返回从1到n中1的出现次数
#include <iostream>
#include <cstdio>
using namespace std;
int main()
{
int n;
scanf("%d", &n);
int sum = 0;
int k;
for(int i = 1; k = n / i;i *= 10)
{
sum += k/10 * i;
int tem = k % 10;
if(tem > 1)
sum += i;
if(tem == 1)
sum += n - k*i + 1;
}
printf("%d\n", sum);
return 0;
}