# 贪心算法-移除k个数让数串尽可能小

```python
'''
已知一个使用字符串表示的非负整数num，将num中的k个数字移除，求移除k个数字后，可以获得的最小的可能的新数字。
输入 : num = “1432219” , k = 3 在去掉3个数字后得到的很多很多可能里，如1432、4322、2219、1219、1229...;
去掉数字4、3、2得到的1219最小
'''

def new_num(str_num, k):
    stack_num = []
    stack_num.append(str_num[0])
    for i in range(1, len(str_num)):
        # 首字母 不能0
        if len(stack_num) > 0 and int(str_num[i]) < int(stack_num[-1]) and k > 0:
            stack_num.pop()
            k -= 1

        if len(stack_num) > 0 or str_num[i] != '0':
            stack_num.append(str_num[i])

    str_num = ''.join(stack_num)

    return str_num


if __name__ == '__main__':
    s = new_num('1432219', 3)
    print(s)
    s = new_num('100200', 1)
    print(s)
'''
1219
200
'''
```


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