给定一个由n个整数和一个整数X组成的数组arr [] ,任务是通过多次执行以下操作,找到使所有数组元素大于或等于0所需的最低成本:
- 将任何数组元素增加1。成本= 1。
- 将所有数组元素加1。成本=X。
例子:
Input: arr[] = {-1, -3, 3, 4, 5}, X = 2
Output: 4
Explanation:
Increment arr[0] by 1. The array arr[] modifies to {0, -3, 3, 4, 5}. Cost = 1.
Increment arr[1] by 1 thrice. The array arr[] modifies to {0, 0, 3, 4, 5}. Therefore, Cost = 4.
Hence, the total cost required is 4.
Input: arr[] = {-3, -2, -1, -5, 7}, X = 2
Output: 8
方法:想法是使用贪婪方法解决问题。请按照以下步骤解决问题:
- 以升序对数组arr []进行排序。
- 初始化一个辅助向量,例如list,以存储负数组元素。
- 初始化一个变量cost = 0,以存储使当前数组元素为0所需的成本,并初始化另一个变量min_cost = INT_MAX ,以存储使所有数组元素> = 0的最终最小成本。
- 遍历数组arr []并尝试通过应用适当的操作来转换列表> = 0中的所有数组元素,并相应地更新min_cost 。
- 打印min_cost的值作为答案。
下面是上述方法的实现:
C++
// C++ program for the above approach
#include
using namespace std;
// Function to find the minimum
// cost to make all array elements
// greater than or equal to 0
void minCost(int arr[], int N, int X)
{
// Sort the array in
// ascending order
sort(arr, arr + N);
int sum = 0;
// Stores the cost to make
// current array element >= 0
int cost = 0;
// Stores the cost to make
// all array elements >= 0
int min_cost = INT_MAX;
// Traverse the array and insert all the
// elements which are < 0
for (int i = 0; i < N; i++) {
// If current array element
// is negative
if (arr[i] < 0) {
// Cost to make all array
// elements >= 0
cost = abs(arr[i]) * X
+ (sum - abs(arr[i]) * i);
sum += abs(arr[i]);
// Update curr if ans is minimum
min_cost = min(min_cost, cost);
}
}
// Print the minimum cost
cout << min_cost;
}
// Driver Code
int main()
{
// Given array
int arr[] = { -1, -3, -2, 4, -1 };
// Size of the array
int N = sizeof(arr) / sizeof(arr[0]);
// Given value of X
int X = 2;
// Function call to find minimum
// cost to make all array elements >= 0
minCost(arr, N, X);
return 0;
}
Java
// Java program for the above approach
import java.util.Arrays;
public class GFG
{
// Function to find the minimum
// cost to make all array elements
// greater than or equal to 0
static void minCost(int arr[], int N, int X)
{
// Sort the array in
// ascending order
Arrays.sort(arr) ;
int sum = 0;
// Stores the cost to make
// current array element >= 0
int cost = 0;
int INT_MAX = Integer.MAX_VALUE;
// Stores the cost to make
// all array elements >= 0
int min_cost = INT_MAX;
// Traverse the array and insert all the
// elements which are < 0
for (int i = 0; i < N; i++) {
// If current array element
// is negative
if (arr[i] < 0) {
// Cost to make all array
// elements >= 0
cost = Math.abs(arr[i]) * X
+ (sum - Math.abs(arr[i]) * i);
sum += Math.abs(arr[i]);
// Update curr if ans is minimum
min_cost = Math.min(min_cost, cost);
}
}
// Print the minimum cost
System.out.print(min_cost);
}
// Driver Code
public static void main (String[] args)
{
// Given array
int arr[] = { -1, -3, -2, 4, -1 };
// Size of the array
int N = arr.length;
// Given value of X
int X = 2;
// Function call to find minimum
// cost to make all array elements >= 0
minCost(arr, N, X);
}
}
// This code is contributed by AnkThon
Python3
# Python3 program for the above approach
import sys
# Function to find the minimum
# cost to make all array of elements
# greater than or equal to 0
def mincost(arr, N, X):
# sort the array in
# ascending order
arr.sort()
sum = 0
# stores the count to make
# current array element >=0
cost = 0
# stores the cost to make
# all array elements >=0
min_cost = sys.maxsize
# Traverse the array and insert all the
# elements which are <=0
for i in range(0, N):
# if current array element
# is negtive
if (arr[i] < 0):
# cost to make all array
# elements >=0
cost = abs(arr[i]) * x + (sum - abs(arr[i]) * i)
sum += abs(arr[i])
# update curr if ans is minimum
min_cost = min(min_cost,cost)
# return minimum cost
return min_cost
# Driver code
arr = [-1, -3, -2, 4, -1]
# size of the array
N = len(arr)
# Given value of x
x = 2
# Function call to find minimum
# cost to make all array elements >=0
print(mincost(arr, N, x))
# This code is contributed by Virusbuddah
C#
// C# program for the above approach
using System;
class GFG{
// Function to find the minimum
// cost to make all array elements
// greater than or equal to 0
static void minCost(int[] arr, int N, int X)
{
// Sort the array in
// ascending order
Array.Sort(arr) ;
int sum = 0;
// Stores the cost to make
// current array element >= 0
int cost = 0;
//int INT_MAX = Int32.MaxValue;
// Stores the cost to make
// all array elements >= 0
int min_cost = Int32.MaxValue;
// Traverse the array and insert all the
// elements which are < 0
for(int i = 0; i < N; i++)
{
// If current array element
// is negative
if (arr[i] < 0)
{
// Cost to make all array
// elements >= 0
cost = Math.Abs(arr[i]) * X +
(sum - Math.Abs(arr[i]) * i);
sum += Math.Abs(arr[i]);
// Update curr if ans is minimum
min_cost = Math.Min(min_cost, cost);
}
}
// Print the minimum cost
Console.Write(min_cost);
}
// Driver Code
static public void Main ()
{
// Given array
int[] arr = { -1, -3, -2, 4, -1 };
// Size of the array
int N = arr.Length;
// Given value of X
int X = 2;
// Function call to find minimum
// cost to make all array elements >= 0
minCost(arr, N, X);
}
}
// This code is contributed by susmitakundugoaldanga
Javascript
输出:
5
时间复杂度: O(N * logN)
辅助空间: O(1)