poj1019

#include<iostream> #include<fstream> #include<string.h> #include<stdio.h> #include<stdlib.h> using namespace std; const unsigned int MAX=2147483647; int Num=100000; int* len; unsigned int *sum; int input; void init() { len[0]=0; sum[0]=0; char data[20]; int i; for(i=1;sum[i-1]<=MAX;i++) { sprintf(data,"%d",i); len[i]=len[i-1]+strlen(data); sum[i]=sum[i-1]+len[i]; } Num=i-1; } void solve() { int high=Num; int low=0; int mid; while(low<=high) { mid=(high+low)/2; if(sum[mid]==input) break; else if(sum[mid]<input) low=mid+1; else high=mid-1; } if(sum[mid]==input) { char temp[20]; sprintf(temp,"%d",mid); int temp_len=strlen(temp); printf("%c\n",temp[temp_len-1]); return ; } if(sum[low]>input) low--; int rest=input-sum[low]; high=low+1; low=0; while(low<=high) { mid=(high+low)/2; if(len[mid]==rest) break; else if(len[mid]<rest) low=mid+1; else high=mid-1; } if(rest==len[mid]) { char temp[20]; sprintf(temp,"%d",mid); int temp_len=strlen(temp); printf("%c\n",temp[temp_len-1]); return ; } if(len[low]>rest) low--; char temp[20]; sprintf(temp,"%d",low+1); printf("%c\n",temp[rest-len[low]-1]); } int main() { len=new int[Num]; sum=new unsigned int[Num]; freopen("input.txt","r",stdin); init(); int n; scanf("%d",&n); while(n--) { scanf("%d",&input); solve(); } return 0; }