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ID | 题目 | 提交者 | 结果 | 用时 | 内存 | 语言 | 文件大小 | 提交时间 | 测评时间 |
---|---|---|---|---|---|---|---|---|---|
#708334 | #5426. Drain the Water Tank | Rightt | WA | 0ms | 3832kb | C++14 | 2.3kb | 2024-11-03 21:31:50 | 2024-11-03 21:31:51 |
Judging History
answer
#include <bits/stdc++.h>
#define IOS ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define int long long
using namespace std;
using ll = long long;
using ld = long double;
struct poi{
ll x,y;
poi(){
x=0,y=0;
}
poi(ll xx,ll yy){
x=xx,y=yy;
}
};
poi operator-(poi a,poi b){return poi(a.x-b.x,a.y-b.y);};
ll cro(poi a,poi b){return a.x*b.y-b.x*a.y;}
//ToLeft测试,判断p是否在ab左边(逆时针),1左,-1右,0在线上
int toleft(poi a,poi b,poi p){
ll ans=cro((b-a) , (p-b));
if(ans==0)return 0;
if(ans>0)return 1;
return -1;
}
long long get(ll x1, ll y1, ll x2, ll y2){
return x1 * y2 - x2 * y1;
}
void solve(){
int n;
cin>>n;
ll ans=0;
vector<poi> p(5*n+5);
for(int i=0;i<n;i++){
cin>>p[i].x>>p[i].y;
p[i+3*n]=p[i+4*n]=p[i+2*n]=p[i+n]=p[i];
}
//p.push_back(p[0]);
set<pair<int, int>> se;
for(int i=n*2;i<n*3;i++){
int j=i,k=i;
while(p[k-1].y==p[k].y)k--;
while(p[j+1].y==p[j].y)j++;
if(toleft(p[k-1],p[j+1],p[i])!=1&&p[j+1].y>p[i].y&&p[k-1].y>p[i].y)
ans++;
if (p[i].x == 100 && p[i].y == 0){
//cout << p[k-1].x << ' ' << p[k-1].y << '\n';
//cout << p[j+1].x << ' ' << p[j+1].y << '\n';
//cout << toleft(p[k-1],p[j+1],p[i]) << '\n';
}
// if (se.count({p[i].x, p[i].y})) ans --;
if (toleft(p[k-1],p[j+1],p[i]) == 0){
if (se.count({p[i].x, p[i].y})) ans --;
while (k <= j) se.insert({p[k].x, p[k++].y});
i = j;
}
//if (k-j-1!=1 && p[i].x>)
//cout<<i-n<<' '<<j-n<<' '<<k-n<<' '<<p[j+1].y<<' '<<p[k-1].y<<' '<<p[i].y<<endl;
//i=j;
// while (p[i].y == p[jj].y) jj ++;
// int pre = i - 1;
// if (p[i].y < p[pre].y && p[i].y < p[jj].y){
// if (p[i].y != p[i + 1].y){
// //不在水平线
// ans += get(p[i].x-p[pre].x, p[i].y-p[pre].y, p[jj].x-p[i].x, p[jj].y-p[i].y) > 0;
// }else{
// //水平线
// if (p[i+1].x > p[i].x) ans ++;
// }
// }
}
cout<<ans;
}
signed main(){
IOS;
int t = 1;
// cin >> t;
while (t -- ){
solve();
}
return 0;
}
详细
Test #1:
score: 100
Accepted
time: 0ms
memory: 3832kb
input:
6 0 0 1 1 2 1 3 0 3 2 0 2
output:
2
result:
ok 1 number(s): "2"
Test #2:
score: -100
Wrong Answer
time: 0ms
memory: 3540kb
input:
8 4 4 0 4 0 2 1 2 2 2 2 0 3 0 4 0
output:
3
result:
wrong answer 1st numbers differ - expected: '1', found: '3'