| find the nth digit | 
| Time Limit: 1000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others) | 
| Total Submission(s): 880 Accepted Submission(s): 325 | 
| Problem Description  假设: S1 = 1 S2 = 12 S3 = 123 S4 = 1234 ......... S9 = 123456789 S10 = 1234567891 S11 = 12345678912 ............ S18 = 123456789123456789 .................. 现在我们把所有的串连接起来 S = 1121231234.......123456789123456789112345678912......... 那么你能告诉我在S串中的第N个数字是多少吗? | 
| Input 							输入首先是一个数字K,代表有K次询问。 接下来的K行每行有一个整数N(1 <= N < 2^31)。 | 
| Output 							对于每个N,输出S中第N个对应的数字. | 
| Sample Input 6 1 2 3 4 5 10 | 
| Sample Output 1 1 2 1 2 4 | 
| Author 8600 | 
| Source HDU 2007-Spring Programming Contest - Warm Up (1) | 
| Recommend 8600 | 
/* 加到S65536长度就大于2^31了 */ #include<bits/stdc++.h> using namespace std; int main() { //freopen("C:\\Users\\acer\\Desktop\\in.txt","r",stdin); long long n,t; scanf("%lld",&t); while(t--) { scanf("%lld",&n); long long i; long long s=0; for(i=1;s<n;i++) s+=i; long long cur=n-s+i-1; if(cur%9) printf("%d\n",cur%9); else puts("9"); } }
原文:http://www.cnblogs.com/wuwangchuxin0924/p/5995169.html