Algorithm
Problem Name: 746. Min Cost Climbing Stairs
You are given an integer array cost where cost[i] is the cost of ith step on a staircase. Once you pay the cost, you can either climb one or two steps.
You can either start from the step with index 0, or the step with index 1.
Return the minimum cost to reach the top of the floor.
Example 1:
Input: cost = [10,15,20] Output: 15 Explanation: You will start at index 1. - Pay 15 and climb two steps to reach the top. The total cost is 15.
Example 2:
Input: cost = [1,100,1,1,1,100,1,1,100,1] Output: 6 Explanation: You will start at index 0. - Pay 1 and climb two steps to reach index 2. - Pay 1 and climb two steps to reach index 4. - Pay 1 and climb two steps to reach index 6. - Pay 1 and climb one step to reach index 7. - Pay 1 and climb two steps to reach index 9. - Pay 1 and climb one step to reach the top. The total cost is 6.
Constraints:
2 <= cost.length <= 10000 <= cost[i] <= 999
Code Examples
#1 Code Example with C++ Programming
Code -
C++ Programming
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Output
#2 Code Example with Java Programming
Code -
Java Programming
class Solution {
public int minCostClimbingStairs(int[] cost) {
int n = cost.length;
int first = cost[0];
int second = cost[1];
for (int i = 2; i < n; i++) {
int curr = cost[i] + Math.min(first, second);
first = second;
second = curr;
}
return Math.min(first, second);
}
}
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Output
#3 Code Example with Javascript Programming
Code -
Javascript Programming
const minCostClimbingStairs = function(cost) {
let f1 = cost[0];
let f2 = cost[1];
for (let i = 2; i < cost.length; i++) {
let f_cur = cost[i] + Math.min(f1, f2);
f1 = f2;
f2 = f_cur;
}
return Math.min(f1, f2);
};
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Output
#4 Code Example with Python Programming
Code -
Python Programming
class Solution:
def minCostClimbingStairs(self, cost):
"""
:type cost: List[int]
:rtype: int
"""
for i in range(2,len(cost)): cost[i]+=min(cost[i-1],cost[i-2])
return min(cost[-1],cost[-2])
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Output
#5 Code Example with C# Programming
Code -
C# Programming
using System;
namespace LeetCode
{
public class _0746_MinCostClimbingStairs
{
public int MinCostClimbingStairs(int[] cost)
{
int cost1 = 0, cost2 = 0;
var index = 2;
for (; index < cost.Length; index++)
{
var curr = Math.Min(cost1 + cost[index - 2], cost2 + cost[index - 1]);
cost1 = cost2;
cost2 = curr;
}
return Math.Min(cost1 + cost[index - 2], cost2 + cost[index - 1]);
}
}
}
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Output