Submission #12804

#	Time	Username	Problem	Language	Result	Execution time	Memory
12804		woqja125	전선 연결하기 (GA9_wire)	C++14	0 / 100	0 ms	8240 KiB

wire

#include<stdio.h>
#include<set>
int d[600001];
int l[300001];
int ans[300001];
int p[300001], e[300001];
struct R
{
    int s, e, n;
    R(int _s, int _e, int _n):s(_s), e(_e), n(_n){}
};
bool operator<(const R &A, const R &B){return A.s<B.s;}
int root(int x){return p[x]==x?x:p[x]=root(p[x]);}
int uni(int a, int b){a=root(a);b=root(b);return p[b] = a;}
void chk(int a, int b)
{
    a = root(a);
    b = root(b);
    if(e[a] != 0) uni(e[a], b);
    if(e[b] != 0) a = uni(e[b], a);
    e[a] = b = root(b);
    e[b] = a;
}
int main()
{
    int n, i;
    int t;
    scanf("%d", &n);
    for(i=1; i<=n; i++) p[i] = i;
    for(i=1; i<=2*n; i++)
    {
        scanf("%d", d+i);
        l[d[i]] = i;
    }
    std::set<R> S;
    for(i=1; i<=2*n; i++)
    {
        t = l[d[i]];
        if(t == i) continue;
        int s, end;
        s=10000000; end = -1;
        while(!S.empty() && S.begin()->e <= i) S.erase(S.begin());
        auto it = S.begin();
        for(; it != S.end() && it->s <= t; it=S.begin())
        {
            if(s > it->s) s = it->s;
            if(end < it->e) end = it->e;
//            printf("! %d %d\n", d[i], it->n);
            chk(d[i], it->n);
            S.erase(S.begin());
        }
        int tmp = root(d[i]);
        if(e[tmp] == tmp)
        {
            printf("IMPOSSIBLE");
            return 0;
        }
        if(end!=-1)
            S.insert(R(s, end, e[tmp]));
        S.insert(R(t, t, d[i]));
    }
//  for(i=1; i<=n; i++) printf("%d %d\n", p[i], e[i]);
    t = root(1);
    for(i=1; i<=2*n; i++)
    {
        if(root(d[i]) == t) printf("^");
        else
        {
            printf("v");
            chk(d[i], t);
            t = root(t);
        }
    }
    return 0;
}

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