Solution for:Num Array

Author: edyluisrey

src/leetcode/NumArray.java

@@ -0,0 +1,26 @@
+package leetcode;
+
+public class NumArray {
+	private int[] sums;
+	public static void main(String[] args) {
+		NumArray test = new NumArray(new int[]{-2, 0, 3, -5, 2, -1});
+		System.out.println(test.sumRange(0, 2));
+		System.out.println(test.sumRange(2, 5));
+		System.out.println(test.sumRange(0, 5));
+
+	}
+	
+	public NumArray(int[] nums) {
+		sums = new int[nums.length];
+		if(nums.length>0)
+		    sums[0]= nums[0];
+        for(int i=1; i<nums.length; i++)
+        	sums[i] = sums[i-1]+ nums[i];
+    }
+    
+    public int sumRange(int i, int j) {
+    	if(i==0) return sums[j];
+        return sums[j]-sums[i-1];
+    }
+
+}