Submission #137290

#	Time	Username	Problem	Language	Result	Execution time	Memory
137290		choikiwon	Ancient Books (IOI17_books)	C++17	Compilation error	0 ms	0 KiB

books

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

typedef long long ll;
typedef pair<int, int> pii;

const int maxn = 1000010;

int N, S;
int A[maxn], vis[maxn];
vector<pii> V;

ll minimum_walk(std::vector<int> p, int s) {
	N = p.size();
	S = s;
	for(int i = 0; i < N; i++) {
        A[i] = p[i];
	}

	ll ret = 0;
	for(int i = 0; i < N; i++) {
        if(vis[i]) continue;
        if(A[i] == i) continue;

        int mx = -1e9;

        int u = i;
        while(!vis[u]) {
            vis[u] = 1;
            mx = max(mx, u);

            ret += abs(u - A[u]);
            u = A[u];
        }

        V.push_back(pii(i, mx));
	}

	if(V.size() == 0) return ret;

	int st = V[0].first;
	int ed = V[0].second;

	if(S < st) {
        ret += 2 * (st - S);
	}
	for(int i = 1; i < V.size(); i++) {
        if(ed < V[i].first) {
            ret += 2 * (V[i].first - ed);

            st = V[i].first;
            ed = V[i].second;
            continue;
        }
        ed = max(ed, V[i].second);
	}
	if(ed < S) {
        ret += 2 * (S - ed);
	}

	int mn = 1e9;
	for(int i = 0; i < N; i++) if(vis[i]) mn = min(mn, abs(i - S));
	ret += 2 * mn;

	return ret;
}

int main() {
    int n, s;
    vector<int> p;
    cin >> n >> s;
    p.resize(n);
    for(int i = 0; i < n; i++) cin >> p[i];
    cout << minimum_walk(p, s);
}

Compilation message (stderr)

books.cpp: In function 'll minimum_walk(std::vector<int>, int)':
books.cpp:48:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 1; i < V.size(); i++) {
                 ~~^~~~~~~~~~
/tmp/ccoTs4XJ.o: In function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'
/tmp/ccD1eeau.o:books.cpp:(.text.startup+0x0): first defined here
collect2: error: ld returned 1 exit status