48 | Rotate Image | GoLang

GO/Rotate_Image.go

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+//
+// Link: https://leetcode.com/problems/rotate-image/
+//
+// 48. Rotate Image
+//
+// You are given an n x n 2D matrix representing an image, rotate the image by 90 degrees (clockwise).
+//
+// You have to rotate the image in-place, which means you have to modify the input 2D matrix directly. DO NOT allocate another 2D matrix and do the rotation.
+
+func rotate(matrix [][]int) {
+
+	n := len(matrix)
+
+	for i := range matrix {
+		for j := i; j < n; j++ {
+			temp := matrix[i][j]
+			matrix[i][j] = matrix[j][i]
+			matrix[j][i] = temp
+		}
+	}
+
+	for i := range matrix {
+		for j := 0; j < (n / 2); j++ {
+			temp := matrix[i][j]
+			matrix[i][j] = matrix[i][n-j-1]
+			matrix[i][n-j-1] = temp
+		}
+	}
+}