LeetCode 265: Paint House II

Posted 2020-10-05 keepshuatishuati

class Solution {
    public int minCostII(int[][] costs) {
        if (costs.length == 0) {
            return 0;
        }
        
        int prevMin = 0;
        int prevSecMin = 0;
        int prevMinIndex = -1;
        for (int i = 0; i < costs.length; i++) {
            int min = Integer.MAX_VALUE;
            int secMin = Integer.MAX_VALUE;
            int minIndex = -1;
            for (int j = 0; j < costs[i].length; j++) {
                int value = costs[i][j] + (j == prevMinIndex ? prevSecMin : prevMin);
                if (minIndex == -1 || value < min) {
                    secMin = min;
                    min = value;
                    minIndex = j;
                } else if (value < secMin) {
                    secMin = value;
                }
            }
            
            prevMin = min;
            prevSecMin = secMin;
            prevMinIndex = minIndex;
        }
        
        return prevMin;
    }
}