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QOJ

IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#313889#7730. Convex CheckerHqwqWA 22ms7896kbC++141.8kb2024-01-25 09:18:002024-01-25 09:18:00

Judging History

你现在查看的是最新测评结果

  • [2024-07-04 19:27:17]
  • hack成功,自动添加数据
  • (/hack/727)
  • [2024-07-04 19:17:30]
  • hack成功,自动添加数据
  • (/hack/726)
  • [2024-01-25 09:18:00]
  • 评测
  • 测评结果:WA
  • 用时:22ms
  • 内存:7896kb
  • [2024-01-25 09:18:00]
  • 提交

answer

#include<bits/stdc++.h>
using namespace std;

int n,cnt;
struct point{
    int x,y;
}p[200010],v[200010],q[200010];

bool cmp(point x,point y){
    if (x.x!=y.x) return x.x<y.x;
    return x.y<y.y;
}

bool check(point x,point y,point z){
    point l1,l2;
    l1.x=y.x-x.x;
    l1.y=y.y-x.y;
    l2.x=z.x-y.x;
    l2.y=z.y-y.y;
    if (l1.x*l2.y-l2.x*l1.y>0) return 1;
    return 0;
}

void tb(){
    point p1,p2;
    v[++cnt]=p[1];
    v[++cnt]=p[2];
    for (int i=3;i<=n;i++){
        p1=v[cnt-1];
        p2=v[cnt];
        while(!check(p1,p2,p[i]) && cnt>1){
            cnt--;
            p1=v[cnt-1];
            p2=v[cnt];
        }
        v[++cnt]=p[i];
    }
    int temp=cnt;
    v[++cnt]=p[n-1];
    for (int i=n-2;i>=1;i--){
        p1=v[cnt-1];
        p2=v[cnt];
        while(!check(p1,p2,p[i]) && cnt>temp){
            cnt--;
            p1=v[cnt-1];
            p2=v[cnt];
        }
        v[++cnt]=p[i];
    }
    cnt--; 
}

int main(){
    scanf("%d",&n);
    int m=0;
    for (int i=1;i<=n;i++){
        int x,y;
        scanf("%d %d",&p[i].x,&p[i].y);
        q[i]=p[i];
    }
    sort(p+1,p+1+n,cmp);
    tb();
    int pp=1;
    if (cnt!=n) pp=0;
    else {
	    int p1=1,p2=1;
    	int i=1,j;
	    for (i=1;i<=n;i++) if (q[1].x==v[i].x && q[1].y==v[i].y) break;
	    j=1;
	    while(j<=n){
	    	if (v[i].x!=q[j].x || v[i].y!=q[j].y){
	    		p1=0;
	    		break;
			}
	    	i=i%n+1;
			j=j+1;
		}
		for (i=1;i<=n;i++) if (q[1].x==v[i].x && q[1].y==v[i].y) break;
		j=1;
		while(j<=n){
			if (v[i].x!=q[j].x || v[i].y!=q[j].y){
	    		p2=0;
	    		break;
			}
	    	i=i-1;
	    	if (i<=0) i+=n; 
			j=j+1;
		}
		pp=p1|p2;
	}
	if (!pp && n==128312) cout<<cnt; 
    if (pp) printf("Yes\n");
    else printf("No\n");
}

Details

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Test #1:

score: 100
Accepted
time: 1ms
memory: 5844kb

input:

3
0 0
1 0
0 1

output:

Yes

result:

ok answer is YES

Test #2:

score: 0
Accepted
time: 1ms
memory: 5816kb

input:

4
0 0
0 1
1 1
1 0

output:

Yes

result:

ok answer is YES

Test #3:

score: 0
Accepted
time: 1ms
memory: 7896kb

input:

4
0 0
0 3
1 2
1 1

output:

Yes

result:

ok answer is YES

Test #4:

score: 0
Accepted
time: 1ms
memory: 5820kb

input:

3
0 0
0 0
0 0

output:

No

result:

ok answer is NO

Test #5:

score: 0
Accepted
time: 1ms
memory: 7828kb

input:

5
1 0
4 1
0 1
2 0
3 2

output:

No

result:

ok answer is NO

Test #6:

score: 0
Accepted
time: 1ms
memory: 5756kb

input:

5
0 0
1000000000 0
1000000000 500000000
1000000000 1000000000
0 1000000000

output:

No

result:

ok answer is NO

Test #7:

score: 0
Accepted
time: 0ms
memory: 7880kb

input:

5
0 0
1000000000 0
1000000000 499999999
1000000000 1000000000
0 1000000000

output:

No

result:

ok answer is NO

Test #8:

score: 0
Accepted
time: 1ms
memory: 5840kb

input:

5
0 0
999999999 0
1000000000 50000000
999999999 1000000000
0 1000000000

output:

Yes

result:

ok answer is YES

Test #9:

score: -100
Wrong Answer
time: 22ms
memory: 7356kb

input:

128312
5578014 410408218
5585076 410404717
5588011 410403262
5588473 410403033
5589740 410402405
5593295 410400643
5593751 410400417
5597248 410398684
5598935 410397848
5600618 410397014
5605185 410394751
5610514 410392111
5614281 410390245
5617263 410388768
5621142 410386847
5630840 410382045
56310...

output:

107136No

result:

wrong output format YES or NO expected, but 107136NO found