Add 1232-Check_If_It_Is_A_Straight_Line.java array

carolkao · May 26, 2021 · 00fb6a7 · 00fb6a7
1 parent b8af8e3
commit 00fb6a7
Showing 1 changed file with 20 additions and 0 deletions.
diff --git a/1232-Check_If_It_Is_A_Straight_Line.java b/1232-Check_If_It_Is_A_Straight_Line.java
@@ -0,0 +1,20 @@
+// Tag: Array
+class Solution {
+    public boolean checkStraightLine(int[][] coordinates) {
+        if (coordinates.length <= 2) return true;
+
+        int x0 = coordinates[0][0], y0 = coordinates[0][1];
+        int diffX = coordinates[1][0] - x0;
+        int diffY = coordinates[1][1] - y0;
+        for (int i = 2; i < coordinates.length; i++) {
+            int tmpDiffX = coordinates[i][0] - x0;
+            int tmpDiffY = coordinates[i][1] - y0;
+
+            //     x1 : y1 == x2 : y2 
+            // ==> x1 * y2 == y1 * x2
+            if (diffX * tmpDiffY != diffY * tmpDiffX) return false;
+        }
+
+        return true;
+    }
+}