Contest/src/_20160910_4th_contest/RotateFunction.java

fishercoder1534 · fishercoder1534 · commit a1a4445d6df9 · 2016-09-24T13:15:37.000-07:00
diff --git a/Contest/src/_20160910_4th_contest/RotateFunction.java b/Contest/src/_20160910_4th_contest/RotateFunction.java
@@ -0,0 +1,40 @@
+package _20160910_4th_contest;
+
+//F(k) = 0 * Bk[0] + 1 * Bk[1] + ... + (n-1) * Bk[n-1]
+public class RotateFunction {
+    public int maxRotateFunction(int[] A) {
+        if(A == null || A.length == 0) return 0;
+        int[] F = new int[A.length];
+        int[] B = A;
+        int max = Integer.MIN_VALUE;
+        for(int i = 0; i < A.length; i++){
+            F[i] = compute(B);
+            max = Math.max(max, F[i]);
+            B = rotate(B);
+        }
+        return max;
+    }
+
+    private int compute(int[] b) {
+        int sum = 0;
+        for(int i = 0; i < b.length; i++){
+            sum += i*b[i];
+        }
+        return sum;
+    }
+
+    private int[] rotate(int[] a) {
+        int first = a[0];
+        for(int i = 1; i < a.length; i++){
+            a[i-1] = a[i];
+        }
+        a[a.length-1] = first;
+        return a;
+    }
+    
+    public static void main(String...strings){
+        int[] nums = new int[]{4, 3, 2, 6};
+        RotateFunction test = new RotateFunction();
+        System.out.println(test.maxRotateFunction(nums));
+    }
+}
