Nyoj 1172 Unlucky number

Unlucky number time limit: +Ms | Memory Limit:65535KB Difficulty:0

Describe

We define that only the number of combinations of 1 and 7 in the interval "l,r" are unlucky numbers, for example: 1, 7, 11, 17 are unlucky numbers, and 13, 27 is not, ask in the interval "l,r" How many unlucky numbers??

Input

There are multiple sets of test data (no more than 100 groups)
Enter two integers per group l,r (0 =< l<= R <= 10^18)

Output

Enter one result per line

Sample input

1 7

Sample output

2

Uploaded by

Acm_ Zhang Shujun

Idea: The same as the ugly number of ideas with the preceding number to facilitate the number of the following

Make a watch.

Then judge the position of the l,r in the table, statistics unlucky numbers on the line

#include <iostream> #include <stdio.h> #include <string.h> #include <algorithm>using namespace Std;long Long a[1000000];int c;void init () {    c=0;    A[c++]=1;    a[c++]=7;    int k=0;    while (A[c-1]<1e18)    {        a[c++]=a[k]*10+1;        a[c++]=a[k]*10+7;        k++;}    } int main () {    init ();    Long long l,r;    while (Cin>>l>>r)    {        int l=0,r=0;        for (int i=0; i<c; i++)        {            if (a[i]<=l) l=i;            if (a[i]>r)            {                r=i;                break;            }        }        if (a[l]==l| | l==0) l--;        printf ("%d\n", R-l-1);}    }        

Nyoj 1172 Unlucky number