算法训练 简单加法(基本型)

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 1 #include<stdio.h>
 2 
 3 int main()
 4 {
 5     int n, i, unit, decade, hundred, kilo, count = 0;
 6     scanf("%d", &n);
 7     for(i = 0; i < n; i++)
 8     {
 9         unit = i % 10;
10         decade = i / 10 % 10;
11         hundred = i / 100 % 10;
12         kilo = i / 1000;
13         if(unit <= 2 && decade <= 2 && hundred <= 2 && kilo <= 2)
14         {
15             count++;
16         }
17     }
18     printf("%d\n", count);
19     return 0;
20 }