JAVASCRIPT

120. Triangle - JavaScript Solution With Explantion

const minimumTotal = function(triangle) {
    const len = triangle.length
    const map = triangle[len - 1]
	/**
	* Example: [
	*     [2],
	*    [3,4],
	*   [6,5,7],
	*  [4,1,8,3]
	* ]
	* map = [4,1,8,3]
	*/
    for (let i = len - 2; i >= 0; i--) {
        for (let j = 0; j <= i; j++) {
            map[j] = Math.min(map[j], map[j + 1]) + triangle[i][j]
			/**
			*  first loop,  
			*  map[0] = Math.min(4 , 1) + 6 = 7
			*  map[1] = Math.min(1 , 8) + 5 = 6
			*  map[2] = Math.min(8 , 3) + 7 = 10
			*  
			*  second loop,  
			*  map[0] = Math.min(7 , 6) + 3 = 9
			*  map[1] = Math.min(6 , 10) + 4 = 10
			*  
			*  third loop,  
			*  map[0] = Math.min(9 , 10) + 2 = 11
			*/
        }
    } 
    return map[0]
}