Create random_point_in_nonoverlapping_rect.cpp

Author: avidLearnerInProgress

random_point_in_nonoverlapping_rect.cpp

@@ -0,0 +1,31 @@
+class Solution {
+    vector<vector<int>> rect;
+    vector<int> area;
+    int n,tarea;
+public:
+    Solution(vector<vector<int>>& rects) {
+        n = rects.size();
+        this->rect = rects;
+        for(int i=0;i<n;i++){
+            
+            int x1 = rects[i][0], x2 = rects[i][2];
+            int y1 = rects[i][1], y2 = rects[i][3];
+            int dx = x2-x1+1, dy = y2-y1+1;
+            int a = abs(dx*dy);
+            i==0?area.push_back(a):area.push_back(a+area[i-1]);
+        }
+        tarea = area[n-1];
+    }
+    
+    vector<int> pick(){
+        int randArea = rand()%tarea;
+        int idx = upper_bound(area.begin(),area.end(),randArea) - area.begin();
+        int x1 = rect[idx][0], x2 = rect[idx][2];
+        int y1 = rect[idx][1], y2 = rect[idx][3];
+        int dx = x2-x1+1, dy = y2-y1+1;
+        int X = x1 + rand()%dx;
+        int Y = y1 + rand()%dy;
+        return {X,Y};
+        
+    }
+};