Solve Problem 410 - Split Array Largest Sum

Author: Hieu Luong

src/binarysearch/Problem410_SplitArrayLargestSum.java

@@ -0,0 +1,36 @@
+package binarysearch;
+
+public class Problem410_SplitArrayLargestSum {
+
+    public int splitArray(int[] A, int m) {
+        int max = 0; long sum = 0;
+        for (int a : A) {
+            max = Math.max(max, a);
+            sum += a;
+        }
+
+        if (m == 1) return (int)sum;
+
+        long lo = max, hi = sum;
+        while (lo <= hi) {
+            long mid = (lo+hi)/2;
+            if (isValid(A, m, mid)) hi = mid-1;
+            else lo = mid+1;
+        }
+
+        return (int)lo;
+    }
+
+    private boolean isValid(int[] A, int m, long max) {
+        int sum = 0, count = 1;
+        for (int a : A) {
+            sum += a;
+            if (sum > max) {
+                sum = a;
+                count++;
+                if (count > m) return false;
+            }
+        }
+        return true;
+    }
+}