Submission #960950

#	Time	Username	Problem	Language	Result	Execution time	Memory
960950		MarwenElarbi	Ancient Books (IOI17_books)	C++17	Compilation error	0 ms	0 KiB

books

#include <bits/stdc++.h>
#include "books.h"
using namespace std;
long long minimum_walk(std::vector<int> p, int s){
    int n=p.size();
    long long ans=0;
    bool vis[n];
    vector<int> cycles(n);
    memset(vis,0,sizeof vis);
    for (int i = 0; i < n; ++i)
    {
        ans+=abs(p[i]-i);
    }
    int en=n-1;
    for (int i = n-1; i >= 0; --i)
    {
        en=i;
        if(p[i]!=i) break;
    }
    //cout << ans<<endl;
    for (int i = 0; i < n; ++i)
    {
        int cur=i;
        if(vis[cur]) continue;
        int mn=1e6+5;
        int mx=-1;
        while(vis[cur]==0){
            vis[cur]=1;
            mx=max(mx,cur);
            mn=min(mn,cur);
            cur=p[cur];
        }
        cycles[mn]++;
        cycles[mx]--;
    }
    int cur=0;
    for (int i = 0; i < en; ++i)
    {
        cur+=cycles[i];
        if(cur==0) ans+=2;
    }
    return ans;
}
int main() {
    #ifndef ONLINE_JUDGE
        freopen("input.txt", "r", stdin);
        freopen("output.txt", "w", stdout);
    #endif
    int n, s;
    assert(2 == scanf("%d %d", &n, &s));

    vector<int> p((unsigned) n);
    for(int i = 0; i < n; i++)
        assert(1 == scanf("%d", &p[(unsigned) i]));

    long long res = minimum_walk(p, s);
    printf("%lld\n", res);

    return 0;
}

Compilation message (stderr)

books.cpp: In function 'int main()':
books.cpp:46:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   46 |         freopen("input.txt", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
books.cpp:47:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   47 |         freopen("output.txt", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/bin/ld: /tmp/cc0HuvLo.o: in function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/ccCK0Ktq.o:books.cpp:(.text.startup+0x0): first defined here
collect2: error: ld returned 1 exit status