Submission #12165

#	Time	Username	Problem	Language	Result	Execution time	Memory
12165		xhae	전선 연결하기 (GA9_wire)	C++14	0 / 100	4 ms	11204 KiB

wire

#include <cstdio>
#include <algorithm>
#include <stack>
#include <vector>

using namespace std;

int n, data[600000];
vector<int> loc[300000];

stack<int> upper, lower;
char ans[600001];

int main(void)
{
	scanf("%d", &n);
	for(int i = 0; i < n * 2; i++)
	{
		scanf("%d", data + i);
		data[i]--;
		loc[data[i]].push_back(i);
	}

	for(int i = 0; i < n * 2; i++)
	{
		if(upper.size() > 0 && upper.top() == i) { upper.pop(); ans[i] = '^'; }
		else if(lower.size() > 0 && lower.top() == i) { lower.pop(); ans[i] = 'v'; }
		else
		{
			int v = data[i];
			int end = loc[v][1];

			if(upper.size() > 0 && lower.size() > 0)
			{
				if(upper.top() < lower.top())
				{
					if(end < upper.top()) { ans[i] = '^'; upper.push(end); }
					else if(end < lower.top()) { ans[i] = 'v'; lower.push(end); }
					else { ans[0] = 0; break; }
				}
				else
				{
					if(end < lower.top()) { ans[i] = 'v'; lower.push(end); }
					else if(end < upper.top()) { ans[i] = '^'; upper.push(end); }
					else { ans[0] = 0; break; }
				}
			}
			else if(upper.size() > 0)
			{
				if(end < upper.top()) { ans[i] = '^'; upper.push(end); }
				else { ans[i] = 'v'; lower.push(end); }
			}
			else if(lower.size() > 0)
			{
				if(end < lower.top()) { ans[i] = 'v'; lower.push(end); }
				else { ans[i] = '^'; upper.push(end); }
			}
			else { upper.push(end); ans[i] = '^'; }
		}
	}

	if(ans[0] == 0) printf("IMPOSSIBLE\n");
	else printf("%s\n", ans);

	return 0;
}

• Subtask 1: 0 / 9
• Subtask 2: 0 / 15
• Subtask 3: 0 / 37
• Subtask 4: 0 / 39