解题提示

1. 逐个计算立方体的相交区域
2. 注意处理立方体不相交的情况
3. 相交立方体的边界计算是关键

#include <iostream>
#include <cstdio>

using namespace std;

struct Point {
    int x, y, z;
};

int main()
{
    Point a, b, c;
    int n, d;
    while(~scanf("%d", &n) && n) {
        scanf("%d %d %d %d", &a.x, &a.y, &a.z, &d);
        b.x = a.x + d;
        b.y = a.y + d;
        b.z = a.z + d;
        for(int i = 1; i < n; i++) {
            scanf("%d %d %d %d",&c.x, &c.y, &c.z, &d);
            a.x = max(c.x, a.x);
            a.y = max(c.y, a.y);
            a.z = max(c.z, a.z);
            b.x = min(c.x + d, b.x);
            b.y = min(c.y + d, b.y);
            b.z = min(c.z + d, b.z);
        }
        printf("%d\n", max((b.x - a.x) * (b.y - a.y) * (b.z - a.z), 0));
    }

    return 0;
}