leetcode-daily/cpp/2204/220426-CN.cpp

33 lines
1.1 KiB
C++

#include <vector>
#include <algorithm>
#include <numeric>
/**
* 883. Projection Area of 3D Shapes
* You are given an n x n grid where we place some 1 x 1 x 1 cubes that are axis-aligned with the x, y, and z axes.
* Each value v = grid[i][j] represents a tower of v cubes placed on top of the cell (i, j).
* We view the projection of these cubes onto the xy, yz, and zx planes.
* A projection is like a shadow, that maps our 3-dimensional figure to a 2-dimensional plane. We are viewing the "shadow" when looking at the cubes from the top, the front, and the side.
* Return the total area of all three projections.
*/
class Solution {
public:
static int projectionArea(const std::vector<std::vector<int>>& G) {
const int n = G.size();
int xy = 0, yz = 0, zx = 0;
std::for_each(G.begin(), G.end(), [&](const std::vector<int>& v) {
xy += std::count_if(v.begin(), v.end(), [](int x) { return x > 0; });
zx += *std::max_element(v.begin(), v.end());
});
for (int i = 0; i < n; ++i) {
int t = 0;
for (int j = 0; j < n; ++j) {
t = std::max(t, G[j][i]);
}
yz += t;
}
return xy + yz + zx;
}
};