From 3306a93b918f9c3fd6f73beece83f0abcafe0eb0 Mon Sep 17 00:00:00 2001
From: Shafaqun Nisa <nisashafaqun@gmail.com>
Date: Sun, 5 Oct 2025 11:10:46 +0530
Subject: [PATCH] 1007. Minimum Domino Rotations For Equal Row.cpp

---
 ...Minimum Domino Rotations For Equal Row.cpp | 44 +++++++++++++++++++
 1 file changed, 44 insertions(+)
 create mode 100644 1007. Minimum Domino Rotations For Equal Row.cpp

diff --git a/1007. Minimum Domino Rotations For Equal Row.cpp b/1007. Minimum Domino Rotations For Equal Row.cpp
new file mode 100644
index 0000000..fde3488
--- /dev/null
+++ b/1007. Minimum Domino Rotations For Equal Row.cpp	
@@ -0,0 +1,44 @@
+class Solution {
+public:
+    int minDominoRotations(vector<int>& tops, vector<int>& bottoms) {
+        const int n = tops.size();
+
+        // Try to make all values equal to tops[0] or bottoms[0]
+        int X=tops[0], Y=bottoms[0];
+        int swapXT=0, swapXB=0;
+        int swapYT=0, swapYB=0;
+
+        bool hasX=1, hasY=1;
+
+        for (int i=0; i<n; i++) {
+            // Check for candidate X
+            if (hasX) {
+                if (tops[i]!=X && bottoms[i]!=X) 
+                    hasX=0;
+                else {
+                    if (tops[i]!=X) swapXT++;
+                    if (bottoms[i]!=X) swapXB++;
+                }
+            }
+
+            // Check for candidate Y
+            if (hasY) {
+                if (tops[i]!=Y && bottoms[i]!=Y) 
+                    hasY=0;
+                else {
+                    if (tops[i]!=Y) swapYT++;
+                    if (bottoms[i]!=Y) swapYB++;
+                }
+            }
+
+            // Early exit if both invalid
+            if (!hasX && !hasY) return -1;
+        }
+
+        int ans=INT_MAX;
+        if (hasX) ans=min(ans, min(swapXT, swapXB));
+        if (hasY) ans=min(ans, min(swapYT, swapYB));
+
+        return ans;
+    }
+};