Submission #12773

#	Time	Username	Problem	Language	Result	Execution time	Memory
12773		Qwaz	전선 연결하기 (GA9_wire)	C++14	0 / 100	0 ms	7068 KiB

wire

#include <cstdio>
#include <queue>
#include <algorithm>

using namespace std;
typedef pair < int, int > pii;

const int MAX = 300020;

int n, data[MAX*2];

void input(){
	scanf("%d", &n);

	for(int i = 0; i < 2*n; i++)
		scanf("%d", &data[i]);
}

pii upStack[MAX];
int top, status[MAX];
priority_queue < pii > down;

void solve(){
	for(int i = 0; i < 2*n; i++){
		int now = data[i];

		if(status[now] == 0){
			status[now] = 1;
			upStack[top++] = pii(i, now);
		} else if(status[now] == 1){
			for(; upStack[top-1].second != now; top--){
				status[upStack[top-1].second] = 2;
				down.push(upStack[top-1]);
			}
			top--;
		} else {
			if(down.top().second != now){
				puts("IMPOSSIBLE");
				return;
			} else
				down.pop();
		}
	}

	for(int i = 0; i < 2*n; i++){
		if(status[data[i]] == 1) putchar('^');
		else putchar('v');
	}
	puts("");
}

int main(){
	input();

	solve();

	return 0;
}

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