add new solutions

solutions/0/q2/solution.go

@@ -0,0 +1,35 @@
+package q2
+
+type ListNode struct {
+	Val  int
+	Next *ListNode
+}
+
+func addTwoNumbers(l1 *ListNode, l2 *ListNode) *ListNode {
+	retRoot := &ListNode{}
+
+	p := retRoot
+	carry := 0
+	for l1 != nil || l2 != nil {
+		val := carry
+		if l1 != nil {
+			val += l1.Val
+			l1 = l1.Next
+		}
+		if l2 != nil {
+			val += l2.Val
+			l2 = l2.Next
+		}
+
+		carry, val = val/10, val%10
+		node := &ListNode{Val: val}
+		p.Next = node
+		p = node
+	}
+	if carry > 0 {
+		p.Next = &ListNode{Val: carry}
+	}
+	return retRoot.Next
+}
+
+var _ = addTwoNumbers

solutions/0/q72/solution.go

@@ -0,0 +1,36 @@
+package q72
+
+func make2d[T any](rows, cols int) [][]T {
+	alloc := make([]T, rows*cols)
+	ret := make([][]T, rows)
+	for i := range ret {
+		ret[i] = alloc[cols*i : cols*(i+1)]
+	}
+	return ret
+}
+
+func minDistance(word1 string, word2 string) int {
+	minDists := make2d[int](len(word1)+1, len(word2)+1)
+
+	for i1 := range len(word1) {
+		minDists[i1+1][0] = i1 + 1
+	}
+	for i2 := range len(word2) {
+		minDists[0][i2+1] = i2 + 1
+	}
+
+	for i1 := 1; i1 <= len(word1); i1++ {
+		for i2 := 1; i2 <= len(word2); i2++ {
+			if word1[i1-1] == word2[i2-1] {
+				minDists[i1][i2] = minDists[i1-1][i2-1]
+			} else {
+				minDists[i1][i2] = min(
+					minDists[i1-1][i2], minDists[i1][i2-1], minDists[i1-1][i2-1],
+				) + 1
+			}
+		}
+	}
+	return minDists[len(word1)][len(word2)]
+}
+
+var _ = minDistance

solutions/0/q74/solution.go

@@ -0,0 +1,23 @@
+package q74
+
+func searchMatrix(matrix [][]int, target int) bool {
+	w, h := len(matrix[0]), len(matrix)
+	idx := func(i int) (int, int) { return i / w, i % w }
+
+	l, r := 0, w*h
+	for l < r {
+		m := (l + r) / 2
+		row, col := idx(m)
+		switch {
+		case matrix[row][col] == target:
+			return true
+		case matrix[row][col] < target:
+			l = m + 1
+		default:
+			r = m
+		}
+	}
+	return false
+}
+
+var _ = searchMatrix