剑指offer 面试题17：打印1到最大的n位数

剑指offer 面试题17：打印1到最大的n位数

题目

输入数字n,按顺序打印出从1到最大的n位十进制数。
比如：输入3，则输出 1、2、3 、、、一直到最大的3位数999

代码

#include <iostream>
#include <string>
using namespace std;

bool Increment(char* number) {// 自增函数
    bool isoverflow = false;
    int istakeon = 0;
    int nlen = strlen(number);
    for (int i = nlen - 1; i >= 0; i--) {//从低位开始
        int up = number[i] - '0' + istakeon;
        if (i == nlen - 1)
            up++;
        if (up >= 10) {
            if (i == 0) {
                isoverflow = true;//超出最高位
            }
            else {
                istakeon = 1;//
                up -= 10;
                number[i] = '0' + up;
            }
        }
        else {
            number[i] = '0' + up;//增加
            break;
        }
    }
    return isoverflow;
}

void printnum(char* number) {
    bool isbegin0 = true;
    int nlen = strlen(number);
    for (int i = 0; i < nlen; i++) {
        if (isbegin0 && number[i] != '0') {
            isbegin0 = false;
        }

        if (!isbegin0)
        {
            printf("%c ", number[i]);
        }

    }
    printf("\t");
}

char** creatnum(int n)
{
    char** p_number = NULL;
    char* number = new char[n + 1];
    p_number = &number;
    memset(number, '0', n);
    number[n] = '\0';
    return p_number;
}

int main() {
    int n = 0;
    cin >> n;

    char* number = *(creatnum(n));
    cout << number << endl;
    while (!Increment(number)) {
        printnum(number);
    }
    delete number;
    return 0;
}