1.题面
点击打开链接
2.题意
给出两个多边形，问这两个多边形能否由一条直线切割长方形得到。
3.思路
有一个测试点死活过不去，还在纠结，代码先晒在这里。
4.代码
/*****************************************************************
> File Name: cpp_acm.cpp
> Author: Uncle_Sugar
> Mail: [email protected]
> Created Time: Tue 21 Feb 2017 03:25:16 CST
*****************************************************************/
# include <cstdio>
# include <cstring>
# include <cctype>
# include <cmath>
# include <cstdlib>
# include <climits>
# include <iostream>
# include <iomanip>
# include <set>
# include <map>
# include <vector>
# include <stack>
# include <queue>
# include <algorithm>
using namespace std;
# define rep(i,a,b) for (i=a;i<=b;i++)
# define rrep(i,a,b) for (i=b;i>=a;i--)
# define mset(aim, val) memset(aim, val, sizeof(aim))
struct QuickIO{
QuickIO(){const int SZ = 1<<20;
setvbuf(stdin ,new char[SZ],_IOFBF,SZ);
setvbuf(stdout,new char[SZ],_IOFBF,SZ);
} //*From programcaicai*//
}QIO;
template<class T>void PrintArray(T* first,T* last,char delim=' '){
for (;first!=last;first++) cout << *first << (first+1==last?'\n':delim);
}
/*
1.see the size of the input data before you select your algorithm
2.cin&cout is not recommended in ACM/ICPC
3.pay attention to the size you defined, for instance the size of edge is double the size of vertex
*/
const int debug = 1;
// const int size = 10 + ;
const int INF = INT_MAX>>1;
const double eps = 1e-7;
typedef long long ll;
struct Point{
double x, y;
Point(){}
Point(double _x, double _y):x(_x), y(_y){}
};
typedef Point Vector;
Vector operator - (const Point& p1, const Point& p2){
return Vector(p1.x - p2.x, p1.y - p2.y);
}
double DotProduct(const Vector& v1, const Vector& v2){
return v1.x*v2.x + v1.y*v2.y;
}
double Length(const Vector v){
return sqrt(DotProduct(v, v));
}
double CrossProduct(const Vector& v1, const Vector& v2){
return v1.x*v2.y - v1.y*v2.x;
}
vector<Point> vct[2];
vector<Vector> special[2];
vector<double> edgelength[2];
int main(){
// std::ios::sync_with_stdio(false);cin.tie(0);
int T; scanf("%d", &T);
while (T--){
for (int i = 0; i < 2; i++) {
special[i].clear();
vct[i].clear();
edgelength[i].clear();
}
int ans = 1;
for (int ii = 0; ii < 2; ii++){
int k;scanf("%d", &k);
while (k--){
Point tp;scanf("%lf%lf", &tp.x, &tp.y);
vct[ii].push_back(tp);
}
}
for (int ii = 0; ii < 2; ii++){
int t = -1;
for (int i = 0; i < vct[ii].size()-1; i++){
int j = (i+1)%vct[ii].size();
int k = (i+2)%vct[ii].size();
// cout << CrossProduct(vct[ii][j] - vct[ii][i], vct[ii][k] - vct[ii][i]) << " ";
if (t == -1) t = (CrossProduct(vct[ii][j] - vct[ii][i], vct[ii][k] - vct[ii][i]) < 0);
else if (t != (CrossProduct(vct[ii][j] - vct[ii][i], vct[ii][k] - vct[ii][i]) < 0)){
ans = 0;
break;
}
}
// cout << endl;
}
if (!ans){
printf("NO\n");
continue;
}
for (int ii = 0; ii < 2; ii++){
for (int i = 0; i < vct[ii].size(); i++){
int j = (i+1)%vct[ii].size();
Vector v = vct[ii][j] - vct[ii][i];
edgelength[ii].push_back(Length(v));
if (abs(v.x) > eps && abs(v.y) > eps){
special[ii].push_back(v);
}
}
}
// cout << special[0].size() << " " << special[1].size() << endl;
if (
!(special[0].size() == special[1].size() && (special[0].size() == 0 || special[1].size() == 1))
){
printf("NO\n");
continue;
}
if (special[0].size() == 0){
ans = 0;
for (int i = 0; i < 4; i++){
for (int j = 0; j < 4; j++){
if (abs(edgelength[0][i] - edgelength[1][j]) < eps){
ans = 1;
break;
}
}
if (ans == 1)
break;
}
if (ans)
printf("YES\n");
else
printf("NO\n");
}else if (special[0].size() == 1){
for (int i = 0; i < 2; i++){
special[i][0].x = abs(special[i][0].x);
special[i][0].y = abs(special[i][0].y);
if (special[i][0].x < special[i][0].y)
swap(special[i][0].x, special[i][0].y);
}
if (Length(special[0][0] - special[1][0]) < eps)
printf("YES\n");
else
printf("NO\n");
}
}
return 0;
}