Leetcode #746: Min Cost Climbing Stairs

Leetcode_0746.cpp

class Solution {
public:
    int minCostClimbingStairs(vector<int>& cost) {
        int n = cost.size();
        if (n == 0) {
            return 0;
        }
        if (n == 1) {
            return cost[0];
        }
        vector<int> dp(n);
        dp[0] = cost[0];
        dp[1] = cost[1];
        for (int i=2; i<n; i++) {
            dp[i] = cost[i]+min(dp[i-1], dp[i-2]);
        }
        return min(dp[n-1], dp[n-2]);
    }
};
// Note: Space complexity of this solution can be reduced to O(1) by using 3-4 variables instead of an array/vector.