Poj 1019
传送门:http://poj.org/problem?id=1019
主要是找数学规律
然后用好pow和log函数,由于数组过大,数组的类型用unsigned
1 #include<iostream> 2 #include<cmath> 3 using namespace std; 4 5 int t; 6 int k; 7 int n; 8 unsigned a[31269]; 9 int m; 10 11 int main(){ 12 cin>>t; 13 a[0]=0; 14 for(int i=1;i<31269;i++){ 15 a[i]=a[i-1]+int(log10(double(i)))+1; 16 }//打表 17 while(t--){ 18 cin>>k; 19 n=1; 20 while(a[n]<k){ 21 k-=a[n]; 22 n++; 23 } 24 m=1; 25 int q=int(log10(double(m)))+1; 26 while(q<k){ 27 k-=q; 28 m++; 29 q=int(log10(double(m)))+1; 30 } 31 cout<<m/int(pow(double(10),double(q-k)))%10<<endl; 32 33 } 34 }