223. Rectangle Area

• Difficulty: Medium

• Topics: Math

• Similar Questions:

  • Rectangle Overlap

Problem:

Find the total area covered by two rectilinear rectangles in a 2D plane.

Each rectangle is defined by its bottom left corner and top right corner as shown in the figure.

Example:

Input: A = -3, B = 0, C = 3, D = 4, E = 0, F = -1, G = 9, H = 2
Output: 45

Note:

Assume that the total area is never beyond the maximum possible value of int.

Solutions:

class Solution {
public:
    int computeArea(int A, int B, int C, int D, int E, int F, int G, int H) {
        return - overlap(A, C, E, G) * overlap(F, H, B, D) + area(C - A, D - B) + area(G - E, H - F);
    }

    int overlap(int start1, int end1, int start2, int end2) {
        if (start1 > start2) {
            swap(start1, start2);
            swap(end1, end2);
        }
        return min(end1 >= start2 ? end1 - start2 : 0, end2 - start2);
    }

    int area(int a, int b) {
        return a * b;

    }
};