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?
#include<iostream> using namespace std; // 1+2+3+4+5...+8=36 int main(){ int K,n; cin>>K; while(K--){ cin>>n; int ans=n; int acu=0,tmp=1; while(acu+tmp<ans){ acu+=tmp; tmp++; } ans=ans-acu; ans=(ans-1)%9+1; cout<<ans<<endl; } return 0; }