hdu 5298 Solid Geometry Homework（几何）

题目链接：hdu 5298 Solid Geometry Homework

每个圈或者是平面将划分出两个区域，每次把一边区域取反即可。最后判断一下是否满足。

#include <cstdio>
#include <cstring>
#include <vector>
#include <algorithm>

using namespace std;
const int maxn = 3000;
typedef long long ll;

struct Point {
int type;
ll x, y, z;
Point (int type = 0, ll x = 0, ll y = 0, ll z = 0) {
this->type = type;
this->x = x;
this->y = y;
this->z = z;
}
};

struct Shape {
int type;
ll a, b, c, d;
Shape (int type = 0, ll a = 0, ll b = 0, ll c = 0, ll d = 0) {
this->type = type;
this->a = a;
this->b = b;
this->c = c;
this->d = d;
}
bool judge (Point u) {
if (type) {
ll ta = u.x - a, tb = u.y - b, tc = u.z - c;
return ta * ta + tb * tb + tc * tc - d * d > 0;
}
return a * u.x + b * u.y + c * u.z + d > 0;
}
};

int M, N, P, Q, V[maxn];
vector<Shape> s;
vector<Point> p;

void init () {
s.clear();
p.clear();
memset(V, 0, sizeof(V));

ll a, b, c, d;
scanf("%d%d%d%d", &M, &N, &P, &Q);
for (int i = 0; i < M; i++) {
scanf("%lld%lld%lld%lld", &a, &b, &c, &d);
s.push_back(Shape(0, a, b, c, d));
}
for (int i = 0; i < N; i++) {
scanf("%lld%lld%lld%lld", &a, &b, &c, &d);
s.push_back(Shape(1, a, b, c, d));
}
for (int i = 0; i < P; i++) {
scanf("%lld%lld%lld", &a, &b, &c);
p.push_back(Point(0, a, b, c));
}
for (int i = 0; i < Q; i++) {
scanf("%lld%lld%lld", &a, &b, &c);
p.push_back(Point(1, a, b, c));
}
}

void solve () {
if (P == 0) {
for (int i = 0; i < Q; i++)
printf("Both\n");
return;
}

for (int i = 0; i < s.size(); i++) {
for (int j = 0; j < p.size(); j++) {
if (s[i].judge(p[j]))
V[j] ^= 1;
}
}

int yellow = -1;
for (int i = 0; i < p.size(); i++) {
if (p[i].type == 0) {
if (yellow == -1)
yellow = V[i];
else if (yellow != V[i]) {
printf("Impossible\n");
return;
}
}
}

for (int i = 0; i < p.size(); i++) {
if (p[i].type) {
printf("%s\n", V[i] == yellow ? "Y" : "R");
}
}
}

int main () {
int cas;
scanf("%d", &cas);
while (cas--) {
init();
solve();
if (cas)
printf("\n");
}
return 0;
}