Submission #1229747

#	Time	Username	Problem	Language	Result	Execution time	Memory
1229747		BigBadBully	Sorting (IOI15_sorting)	C++20	Compilation error	0 ms	0 KiB

sorting

#include <bits/stdc++.h>
#define int long long
#define pii pair<int, int>
#define ff first
#define ss second
using namespace std;
using ll = long long;
const int mod = 998244353;
const int inf = 1e18;
const int maxn = 5 * 1e5 + 5;
vector<int> fact(maxn + 1, 1);
vector<int> invfact(maxn + 1, 1);

ll exp(ll x, ll n)
{
    assert(n >= 0);
    x %= mod; // note: m * m must be less than 2^63 to avoid ll overflow
    ll res = 1;
    while (n > 0)
    {
        if (n % 2 == 1)
        {
            res = res * x % mod;
        }
        x = x * x % mod;
        n /= 2;
    }
    return res;
}
int inv(int x)
{
    return exp(x, mod - 2);
}

void init()
{
    for (int i = 1; i <= maxn; i++)
        fact[i] = fact[i - 1] * i % mod;
    invfact[maxn] = inv(fact[maxn]);
    for (int i = maxn - 1; i >= 0; i--)
        invfact[i] = invfact[i + 1] * (i + 1) % mod;
}
int ncr(int n, int r)
{
    if (n < r)
        return 0ll;
    return fact[n] * invfact[r] % mod * invfact[n - r] % mod;
}

int sigma(vector<int>&a,vector<int>&b,vector<int>&wher,vector<int>&v,bool mode)
{
    int ans = 0;
    auto f = [&](int i,int j)
    {
        swap(v[i],v[j]);
        ans++;
        if(mode)
        {
            swap(wher[i],wher[j]);
            a.push_back(wher[i]);
            b.push_back(wher[j]);
        }
    };
    int n = v.size();
    
    vector<int> vis(n,0);
    for (int i = 0; i < n; i++)
    {
        if (!vis[i])
        {
            vis[i] = 1;
            int cur = v[i];
            while(!vis[cur])
            {
                vis[cur] = 1;
                auto old = v[cur];
                f(i,cur);
                cur = old;
            }
        }
        
    }
    assert(is_sorted(v.begin(),v.end()));
    return ans;
};

int findSwapPairs
(int N, vector<int>& S, int M, vector<int>& X, vector<int>& Y, 
vector<int>& P, vector<int>& Q)
{
    int n = N;
    auto v = S;
    int m = M;
    auto x = X;
    auto y = Y;
    auto p = P;
    auto q = Q;
    auto check = [&](int t,bool mode)
    {
        vector<int> wher(n),orig(n);
        for (int i = 0; i < n; i++)
            wher[i] = i,orig[i] = i;
        for (int i = 0; i < t; i++)
        {
            swap(v[x[i]],v[y[i]]);
            swap(orig[x[i]],orig[y[i]]);
            swap(wher[orig[x[i]]],wher[orig[y[i]]]);
        }
        int res = sigma(p,q,wher,v,mode);
        return res <= t;
    };
    int l = 0,r = n;
    while(r-l)
    {
        int mid = l+r>>1;
        if (check(mid,0))
            r = mid;
        else
            l = mid+1;
    }
    return check(l,1);
}

Compilation message (stderr)

/usr/bin/ld: /tmp/ccvkeBF2.o: in function `main':
grader.c:(.text.startup+0x4e9): undefined reference to `findSwapPairs(int, int*, int, int*, int*, int*, int*)'
collect2: error: ld returned 1 exit status