| SGU - 105 Div 3
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Description
There is sequence 1, 12, 123, 1234, ..., 12345678910, ... . Given first N elements of that sequence. You must determine amount of numbers in it that are divisible by 3. Input Input contains N (1 Output Write answer to the output. Sample Input Sample Output Source |
数学题！找规律！
规律：0,1,1,0,1,1,0,1,1,0,1,1.... （0代表不能被3整除，1代表能被3整除！）
AC代码：
#include#include #include #include #include using namespace std;int main(){ int n; scanf("%d", &n); int ans = 0; ans += (n/3)*2; if(n%3==2) ans++; printf("%d\n", ans); return 0;}