add new solutions

solutions/36/q3651/solution.go

@@ -0,0 +1,65 @@
+package q3651
+
+import (
+	"math"
+	"slices"
+)
+
+func minCost(grid [][]int, k int) int {
+	w, h := len(grid[0]), len(grid)
+	gridVal := func(coord int) int { return grid[coord/w][coord%w] }
+
+	sortedCoords := make([]int, w*h)
+	for i := range sortedCoords {
+		sortedCoords[i] = (i)
+	}
+	slices.SortFunc(sortedCoords, func(a, b int) int { return gridVal(a) - gridVal(b) })
+
+	cache := make([]int32, w*h)
+	prevMinCosts := make([]int32, len(sortedCoords))
+
+	for tele := range k + 1 {
+		// Precompute min costs
+		if tele > 0 {
+			var curMin int32 = math.MaxInt32
+			i, j := 0, 0
+			for i < len(sortedCoords) {
+				curMin = min(curMin, cache[sortedCoords[i]])
+
+				i++
+				for j < i && (i == len(sortedCoords) || gridVal(sortedCoords[i]) > gridVal(sortedCoords[j])) {
+					prevMinCosts[sortedCoords[j]] = curMin
+					j++
+				}
+			}
+		}
+
+		for r := h - 1; r >= 0; r-- {
+			for c := w - 1; c >= 0; c-- {
+				if r == h-1 && c == w-1 {
+					continue
+				}
+
+				var val int32 = math.MaxInt32
+				if r+1 < h {
+					val = min(val, cache[(r+1)*w+c]+int32(grid[r+1][c]))
+				}
+				if c+1 < w {
+					val = min(val, cache[r*w+c+1]+int32(grid[r][c+1]))
+				}
+
+				if tele == 0 {
+					cache[r*w+c] = val
+					continue
+				}
+
+				// Find min cost with teleports
+				cache[r*w+c] = min(val, prevMinCosts[r*w+c])
+			}
+		}
+	}
+
+	return int(cache[0])
+}
+
+var _ = minCost