[노형민] Day07

leetcode2/1easy/노형민/Q3477.cs

@@ -0,0 +1,34 @@
+public class Solution
+{
+    public int NumOfUnplacedFruits(int[] fruits, int[] baskets)
+    {
+        for (int i = 0; i < fruits.Length; i++)
+        {
+            for (int j = 0; j < baskets.Length; j++)
+            {
+                if (baskets[j] == 0)
+                {
+                    continue;
+                }
+
+                if (fruits[i] <= baskets[j])
+                {
+                    baskets[j] = 0;
+                    fruits[i] = 0;
+                    break;
+                }
+            }
+        }
+
+        int result = 0;
+        for (int i = 0; i < fruits.Length; i++)
+        {
+            if (fruits[i] != 0)
+            {
+                result++;
+            }
+        }
+
+        return result;
+    }
+}

leetcode2/2medium/노형민/Q307.cs

@@ -0,0 +1,83 @@
+public class NumArray
+{
+    int[] _segmentTree;
+
+    public NumArray(int[] nums)
+    {
+        _segmentTree = new int[nums.Length * 4];
+
+        BuildSegmentTree(nums, 0, nums.Length - 1, 0);
+    }
+
+    private int BuildSegmentTree(int[] nums, int start, int end, int index)
+    {
+        if (start == end)
+        {
+            _segmentTree[index] = nums[start];
+
+            return _segmentTree[index];
+        }
+
+        int mid = (start + end) / 2;
+
+        _segmentTree[index] = BuildSegmentTree(nums, start, mid, 2 * index + 1) +
+                              BuildSegmentTree(nums, mid + 1, end, 2 * index + 2);
+        return _segmentTree[index];
+    }
+
+    public void Update(int index, int val)
+    {
+        Update(0, _segmentTree.Length / 4 - 1, 0, index, val);
+    }
+
+    private void Update(int start, int end, int index, int targetIndex, int val)
+    {
+        if (start == end)
+        {
+            _segmentTree[index] = val;
+            return;
+        }
+
+        int mid = (start + end) / 2;
+
+        if (targetIndex <= mid)
+        {
+            Update(start, mid, 2 * index + 1, targetIndex, val);
+        }
+        else
+        {
+            Update(mid + 1, end, 2 * index + 2, targetIndex, val);
+        }
+
+        _segmentTree[index] = _segmentTree[2 * index + 1] + _segmentTree[2 * index + 2];
+    }
+
+    public int SumRange(int left, int right)
+    {
+        return Sum(0, _segmentTree.Length / 4 - 1, 0, left, right);
+    }
+
+    private int Sum(int start, int end, int index, int left, int right)
+    {
+        if (start > right || end < left)
+        {
+            return 0;
+        }
+
+        if (start >= left && end <= right)
+        {
+            return _segmentTree[index];
+        }
+
+        int mid = (start + end) / 2;
+        return Sum(start, mid, 2 * index + 1, left, right) +
+               Sum(mid + 1, end, 2 * index + 2, left, right);
+    }
+}
+
+/**
+ * Your NumArray object will be instantiated and called as such:
+ * NumArray obj = new NumArray(nums);
+ * obj.Update(index,val);
+ * int param_2 = obj.SumRange(left,right);
+ */