find the nth digit

6
1
2
3
4
5
10

1
1
2
1
2
4

#include<cstdio>
#include<string>
#include<cmath>
#include<cstring>
#include<cctype>
#include<cstdlib>
#include<vector>
#include<set>
#include<map>
#include<stack>
#include<queue>
#include<list>
#include<algorithm>
#include<iostream>
#include<sstream>

using namespace std;

int main()
{
    int cas;
    int n;
    int sum;
    scanf("%d", &cas);
    while( cas-- )
    {
        scanf("%d", &n);
        sum = 0;
        for(int i=1; ; i++)
        {
            sum += i;
            if( sum >= n )
            {
                sum -= i;
                break;
            }
        }
        int ans = n - sum;
        if( ans % 9 == 0 ) printf("9\n");
        else printf("%d\n", ans%9);
    }

    return 0;
}

HDU 1597:find the nth digit,布布扣,bubuko.com

HDU 1597:find the nth digit

原文：http://blog.csdn.net/u013487051/article/details/38536337