package nowcoder; public class solution43 { public int NumberOf1Between1AndN_Solution(int n) { int cnt = 0; for(int m = 1;m<=n;m*=10) { //i表示当前分析的是哪一个数位 int a=n/m,b=n%m; cnt += (a+8/10)*m+(a%10==1?b+1:0); } return cnt; } }