Least Number after Deleting Digits-优快云博客

本文介绍了一种算法，该算法能够从输入的数字中通过删除指定数量的数字来找到可能的最小数值。通过逐位比较并删除较大的数字实现目标。提供了一个C语言实现的例子。

Problem: Please get the least number after deleting k digits from the input number. For example, if the input number is 24635, the least number is 23 after deleting 3 digits.

参考：http://codercareer.blogspot.com/2013/11/no-48-least-number-after-deleting-digits.html

/* Copyleft: Ming Lin <minggr@gmail.com> */

#include <stdio.h>

int delete_one(int data[], int i, int n)
{
	int prev = -1;
	int prev_i;

	for (; i < n; i++) {
		if (data[i] == -1)
			continue;
		if (prev == -1) {
			prev_i = i;
			prev = data[i];
			continue;
		}
		if (data[i] < prev)
			break;
		prev_i = i;
		prev = data[i];
	}

	data[prev_i] = -1;

	return prev_i;
}

void print_data(int data[], int n)
{
	int i;	

	for (i = 0; i < n; i++)
		if (data[i] != -1)
			printf("%d", data[i]);
	printf("\n");
}

void least_number(int data[], int n, int k)
{
	int i = 0;

	while (k-- > 0) {
		i = delete_one(data, i, n);
		if (i == 0)
			i = 1;
		else
			i--;
	}
}

int main()
{
	int data[] = {2, 4, 6, 3, 5};
	int n = 5;
	int k = 3;

	print_data(data, n);
	least_number(data, n, k);
	print_data(data, n);

	return 0;
}