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#include<stdio.h> #include<iostream> #include<string.h> #include<set> #include<vector> #include<map> #include<math.h> #include<string> #include<stdlib.h> #include<algorithm> using namespace std; #define N 1000005 #define ll __int64 ll num[10],n; ll go(ll x){ ll ans = x; while(ans>=10){ ans = 0; while(x) { ans += x%10; x /= 10; } x = ans; } return ans; } int main(){ ll i,j,k; while(~scanf("%I64d",&n)) { memset(num, 0, sizeof num); ll ans = 0; for(i=1;i<=n;i++) num[go(i)]++, ans -= n/i; for(j=0;j<10;j++) for(k=0;k<10;k++) ans+=num[k]*num[j]*num[go(k*j)]; printf("%I64d\n",ans); } return 0; } /* 2 1 2 3 1 2 3 */版权声明：本文博主原创文章，博客，未经同意不得转载。
转载于:https://www.cnblogs.com/bhlsheji/p/4803364.html
