add new solutions

solutions/15/q1582/solution.go

@@ -0,0 +1,39 @@
+// Package q1582 implements a solution for https://leetcode.com/problems/special-positions-in-a-binary-matrix/
+package q1582
+
+func numSpecial(mat [][]int) int {
+	hPos := make([]int, len(mat))
+	vPos := make([]int, len(mat[0]))
+	for i := range vPos {
+		vPos[i] = -1
+	}
+
+	for row := range mat {
+		hPos[row] = -1
+		for col, val := range mat[row] {
+			if val == 1 {
+				if hPos[row] >= 0 {
+					hPos[row] = -2
+				} else if hPos[row] == -1 {
+					hPos[row] = col
+				}
+
+				if vPos[col] >= 0 {
+					vPos[col] = -2
+				} else if vPos[col] == -1 {
+					vPos[col] = row
+				}
+			}
+		}
+	}
+
+	pairs := 0
+	for i := range hPos {
+		if hPos[i] >= 0 && vPos[hPos[i]] == i {
+			pairs++
+		}
+	}
+	return pairs
+}
+
+var _ = numSpecial