C 解法, 执行用时: 14ms, 内存消耗: 1292KB, 提交时间: 2022-04-07

/**
 * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
 *
 * 
 * @param n int整型 
 * @return int整型一维数组
 * @return int* returnSize 返回数组行数
 *
 * C语言声明定义全局变量请加上static，防止重复定义
 */
void dfs(int n, int sum, int *ans, int *returnSize)
{
    int base = sum * 10;
    if (base <= n) {
        for (int i = 0; i <= 9; ++i) {
            sum = base + i;
            if (sum <= n && sum != 0) {
                ans[(*returnSize)++] = sum;
                dfs(n, sum, ans, returnSize);
            }
        }
    }
}
int* orderArray(int n, int* returnSize ) {
    // write code here
    int *ans = (int *)malloc(sizeof(int) * 100000);
    *returnSize = 0;
    dfs(n, 0, ans, returnSize);
    return ans;
}

C 解法, 执行用时: 16ms, 内存消耗: 1308KB, 提交时间: 2022-07-08

void back(int n, int sum, int* z, int* returnSize) {
    int a = sum * 10;
    if (a <= n) {
        for (int i = 0; i <= 9; ++i) {
            sum = a + i;
            if (sum <= n && sum != 0) {
                z[(*returnSize)++] = sum;
                back(n, sum, z, returnSize);
            }
        }
    }
}
int* orderArray(int n, int* returnSize ) {
    int* z = (int*)malloc(sizeof(int) * 100000);
    *returnSize = 0;
    back(n, 0, z, returnSize);
    return z;
}

C++ 解法, 执行用时: 16ms, 内存消耗: 1328KB, 提交时间: 2022-06-01

class Solution {
public:
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param n int整型 
     * @return int整型vector
     */
    vector<int> orderArray(int n) {
        // write code here
            vector<int>res(n);
    int tmp = 1;
    for (int i = 0; i < n; i++) {
        res[i] = tmp;
        if (tmp * 10 <= n) {
            tmp *= 10;
        }
        else {
            while (tmp % 10 == 9 || tmp + 1 > n) {
                tmp /= 10;
            }
            tmp++;
        }
    }
    return res;
    }
};

C 解法, 执行用时: 17ms, 内存消耗: 1312KB, 提交时间: 2022-04-05

/**
 * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
 *
 * 
 * @param n int整型 
 * @return int整型一维数组
 * @return int* returnSize 返回数组行数
 *
 * C语言声明定义全局变量请加上static，防止重复定义
 */
void dfs(int n, int sum, int *retBuf, int *returnSize)
{
    int base = sum * 10;
    if (base <= n) {
        for (int i = 0; i <= 9; i++) {
            sum = base + i;
            if (sum <= n && sum != 0) {
                retBuf[*returnSize] = sum;
                (*returnSize) += 1;
                dfs(n, sum, retBuf, returnSize);
            }
        }
    }
}
int* orderArray(int n, int* returnSize ) {
    // write code here
    int *retBuf = malloc(100005 * sizeof(int));
    *returnSize = 0;
    dfs(n, 0, retBuf, returnSize);
    
    return retBuf;
}

C++ 解法, 执行用时: 17ms, 内存消耗: 1412KB, 提交时间: 2022-07-27

class Solution {
public:
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param n int整型 
     * @return int整型vector
     */
    vector<int> orderArray(int n) {
        // write code here
      vector<int> res(n);
      int k = 1;
      for (int i = 0; i < n; i ++)
      {
        res[i] = k;
        if(k * 10 <= n) {
          k *= 10;
        } else {
          while(k % 10 == 9 || k  == n)
            k /= 10;
          k ++;
        }
      }
      return res;
    }
};