LintCode-3.统计数字

class Solution {
    /*
     * param k : As description.
     * param n : As description.
     * return: An integer denote the count of digit k in 1..n
     */
    public int digitCounts(int k, int n) {
        // write your code here
        int sum = 0;
        for(int i = 0; i <= n; i++){
            char[] c = String.valueOf(i).toCharArray();
            for(int j = 0; j < c.length;j++){
                if(c[j] == String.valueOf(k).toCharArray()[0]) sum++;
            }
        }
        return sum;
    }
};