minimum index of a valid split

Author: kwojcicki

Diff for: leetcode/src/solutions/minimum_index_of_a_valid_split.java

@@ -0,0 +1,32 @@
+package solutions;
+
+import java.util.List;
+
+public class minimum_index_of_a_valid_split {
+    public int minimumIndex(List<Integer> nums) {
+        int majority = 0;
+        int count = 0;
+        for(int i: nums) {
+        	if(i == majority) count++;
+        	else if(count == 0) { majority = i; count = 1; }
+        	else count--;
+        }
+        
+        count = 0;
+        for(int i: nums) if(i == majority) count++;
+        
+        // System.out.println(majority + " " + count);
+        int leftCount = 0;
+        for(int i = 0; i < nums.size() - 1; i++) {
+        	if(nums.get(i) == majority) leftCount++;
+            // System.out.println(leftCount + " " + i + " " + count);
+            // System.out.println(((double) leftCount) / (i + 1) + " " + 
+            // (double)(count - leftCount) / (nums.size() - i - 1));
+
+        	if( ((double) leftCount) / (i + 1) > 0.5 && 
+        			(double)(count - leftCount) / (nums.size() - i - 1) > 0.5) return i; 
+        }
+    	
+    	return -1;
+    }
+}