refactor 307

Author: fishercoder1534

src/main/java/com/fishercoder/solutions/_307.java

@@ -1,101 +1,85 @@
 package com.fishercoder.solutions;
 
-/**
- * 307. Range Sum Query - Mutable
- *
- * Given an integer array nums, find the sum of the elements between indices i and j (i ≤ j), inclusive.
-
- The update(i, val) function modifies nums by updating the element at index i to val.
- Example:
- Given nums = [1, 3, 5]
-
- sumRange(0, 2) -> 9
- update(1, 2)
- sumRange(0, 2) -> 8
- Note:
- The array is only modifiable by the update function.
- You may assume the number of calls to update and sumRange function is distributed evenly.
- */
 public class _307 {
 
-	public static class Solution1 {
-		class NumArray {
-			class SegmentTreeNode {
-				SegmentTreeNode left;
-				SegmentTreeNode right;
-				int start;
-				int end;
-				int sum;
+    public static class Solution1 {
+        class NumArray {
+            class SegmentTreeNode {
+                SegmentTreeNode left;
+                SegmentTreeNode right;
+                int start;
+                int end;
+                int sum;
 
-				public SegmentTreeNode(int start, int end) {
-					this.start = start;
-					this.end = end;
-					this.left = null;
-					this.right = null;
-					this.sum = 0;
-				}
-			}
+                public SegmentTreeNode(int start, int end) {
+                    this.start = start;
+                    this.end = end;
+                    this.left = null;
+                    this.right = null;
+                    this.sum = 0;
+                }
+            }
 
-			private SegmentTreeNode root = null;
+            private SegmentTreeNode root = null;
 
-			public NumArray(int[] nums) {
-				root = buildSegmentTree(nums, 0, nums.length - 1);
-			}
+            public NumArray(int[] nums) {
+                root = buildSegmentTree(nums, 0, nums.length - 1);
+            }
 
-			SegmentTreeNode buildSegmentTree(int[] nums, int start, int end) {
-				if (start > end) {
-					return null;
-				} else {
-					SegmentTreeNode root = new SegmentTreeNode(start, end);
-					if (start == end) {
-						root.sum = nums[start];
-					} else {
-						int mid = start + (end - start) / 2;
-						root.left = buildSegmentTree(nums, start, mid);
-						root.right = buildSegmentTree(nums, mid + 1, end);
-						root.sum = root.left.sum + root.right.sum;
-					}
-					return root;
-				}
-			}
+            SegmentTreeNode buildSegmentTree(int[] nums, int start, int end) {
+                if (start > end) {
+                    return null;
+                } else {
+                    SegmentTreeNode root = new SegmentTreeNode(start, end);
+                    if (start == end) {
+                        root.sum = nums[start];
+                    } else {
+                        int mid = start + (end - start) / 2;
+                        root.left = buildSegmentTree(nums, start, mid);
+                        root.right = buildSegmentTree(nums, mid + 1, end);
+                        root.sum = root.left.sum + root.right.sum;
+                    }
+                    return root;
+                }
+            }
 
-			void update(int i, int val) {
-				update(root, i, val);
-			}
+            void update(int i, int val) {
+                update(root, i, val);
+            }
 
-			void update(SegmentTreeNode root, int pos, int val) {
-				if (root.start == root.end) {
-					root.sum = val;
-				} else {
-					int mid = root.start + (root.end - root.start) / 2;
-					if (pos <= mid) {
-						update(root.left, pos, val);
-					} else {
-						update(root.right, pos, val);
-					}
-					root.sum = root.left.sum + root.right.sum;
-				}
-			}
+            void update(SegmentTreeNode root, int pos, int val) {
+                if (root.start == root.end) {
+                    root.sum = val;
+                } else {
+                    int mid = root.start + (root.end - root.start) / 2;
+                    if (pos <= mid) {
+                        update(root.left, pos, val);
+                    } else {
+                        update(root.right, pos, val);
+                    }
+                    root.sum = root.left.sum + root.right.sum;
+                }
+            }
 
-			public int sumRange(int i, int j) {
-				return sumRange(root, i, j);
-			}
+            public int sumRange(int i, int j) {
+                return sumRange(root, i, j);
+            }
 
-			int sumRange(SegmentTreeNode root, int start, int end) {
-				if (root.end == end && root.start == start) {
-					return root.sum;
-				} else {
-					int mid = root.start + (root.end - root.start) / 2;
-					if (end <= mid) {
-						return sumRange(root.left, start, end);
-					} else if (start >= mid + 1) {
-						return sumRange(root.right, start, end);
-					} else {
-						return sumRange(root.right, mid + 1, end) + sumRange(root.left, start, mid);
-					}
-				}
-			}
-		}
-	}
+            int sumRange(SegmentTreeNode root, int start, int end) {
+                if (root.end == end && root.start == start) {
+                    return root.sum;
+                } else {
+                    int mid = root.start + (root.end - root.start) / 2;
+                    if (end <= mid) {
+                        return sumRange(root.left, start, end);
+                    } else if (start >= mid + 1) {
+                        return sumRange(root.right, start, end);
+                    } else {
+                        return sumRange(root.right, mid + 1, end) + sumRange(root.left, start, mid);
+                    }
+                }
+            }
+        }
+    }
 }