Submission #1000170

#TimeUsernameProblemLanguageResultExecution timeMemory
1000170whatthemomooofun1729Sorting (IOI15_sorting)C++17
Compilation error
0 ms0 KiB
#include <iostream> #include <algorithm> #include <utility> #include <vector> #include <stack> #include <map> #include <queue> #include <set> #include <unordered_set> #include <unordered_map> #include <cstring> #include <cmath> #include <functional> #include <cassert> #include <iomanip> #include <numeric> #include <bitset> #include <sstream> #include <chrono> #include <random> #define ff first #define ss second #define PB push_back #define sz(x) int(x.size()) #define rsz resize #define fch(xxx, yyy) for (auto xxx : yyy) // abusive notation #define all(x) (x).begin(),(x).end() #define eps 1e-9 // more abusive notation (use at your own risk): //#define int ll using namespace std; typedef long long ll; typedef long double ld; typedef unsigned long long ull; using pii = pair<int, int>; using pll = pair<ll, ll>; using vi = vector<int>; using vll = vector<ll>; // debugging void __print(int x) {std::cerr << x;} void __print(ll x) {std::cerr << x;} /* remember to uncomment this when not using THE MACRO */ void __print(unsigned x) {std::cerr << x;} void __print(ull x) {std::cerr << x;} void __print(float x) {std::cerr << x;} void __print(double x) {std::cerr << x;} void __print(ld x) {std::cerr << x;} void __print(char x) {std::cerr << '\'' << x << '\'';} void __print(const char *x) {std::cerr << '\"' << x << '\"';} void __print(const string& x) {std::cerr << '\"' << x << '\"';} void __print(bool x) {cerr << (x ? "true" : "false");} template<typename T, typename V> void __print(const pair<T, V> &x) {std::cerr << '{'; __print(x.ff); std::cerr << ", "; __print(x.ss); std::cerr << '}';} template<typename T> void __print(const T& x) {int f = 0; std::cerr << '{'; for (auto &i: x) std::cerr << (f++ ? ", " : ""), __print(i); std::cerr << "}";} void _print() {std::cerr << "]\n";} template <typename T, typename... V> void _print(T t, V... v) {__print(t); if (sizeof...(v)) std::cerr << ", "; _print(v...);} void println() {std::cerr << ">--------------------<" << endl;} #ifndef ONLINE_JUDGE #define debug(x...) cerr << "[" << #x << "] = ["; _print(x) #else #define debug(x...) #endif // templates template <class T> bool ckmin(T &a, const T &b) {return b<a ? a = b, 1 : 0;} template <class T> bool ckmax(T &a, const T &b) {return b>a ? a = b, 1 : 0;} template <class T> using gr = greater<T>; template <class T> using vc = vector<T>; template <class T> using p_q = priority_queue<T>; template <class T> using pqg = priority_queue<T, vc<T>, gr<T>>; template <class T1, class T2> using pr = pair<T1, T2>; mt19937_64 rng_ll(chrono::steady_clock::now().time_since_epoch().count()); int rng(int M) {return (int)(rng_ll()%M);} /*returns any random number in [0, M) */ // const variables constexpr int INF = (int)2e9; constexpr int MOD = 998244353; constexpr ll LL_INF = (ll)3e18; constexpr int mod = (int)1e9 + 7; constexpr ll inverse = 500000004LL; // inverse of 2 modulo 1e9 + 7 void setIO(const string& str) {// fast input/output ios_base::sync_with_stdio(false); cin.tie(nullptr); if (str.empty()) return; freopen((str + ".in").c_str(), "r", stdin); freopen((str + ".out").c_str(), "w", stdout); } vc<pii> findOperations(vector<int> v) { set<pii> st; for (int i = 0; i < sz(v); ++i) { st.insert({v[i], i}); } vc<pii> ops; for (int i = 0; i < sz(v); ++i) { int index = (*st.begin()).ss; if (index != i) { ops.PB({index, i}); // swapping the plates st.erase({v[i], i}); st.insert({v[i], index}); swap(v[i], v[index]); } st.erase(st.begin()); } reverse(all(ops)); return ops; } int findSwapPairs(int N, int* s, int M, int* x, int* y, int* p, int* q) { vc<pii> ans; // answer (the set of operations needed) int l = 0, r = M; // bounds on binary search // note that the array can already be sorted, so l is within [0, M] while (l <= r) { int mid = (l + r) / 2; // assume that 'mid' moves are taken vi v(N); for (int i = 0; i < N; ++i) { v[i] = s[i]; // stores the apples in their original order on the plates from 0 to N - 1 } for (int i = 0; i < mid; ++i) { swap(v[x[i]], v[y[i]]); // now, swap the apples } vc<pii> ops = findOperations(v); // operations that make Aizhan win // ops -> swap the plates under the apples // if we end up with some permutation [v[0], ... v[N]] // we want the plates to be in that same orientation // so we make moves to change [0, 1, 2, ... N] -> [v[0], ... v[N]] // or, alternatively, we change [v[0], ... v[N]] -> [0, 1, 2, ... N] (1) // the latter is the correct version because when we swap the plates, we also swap the apples if (sz(ops) <= mid) { r = mid - 1; } else { l = mid + 1; } } r++; // redo the above operations vi v(N); for (int i = 0; i < N; ++i) { v[i] = s[i]; } for (int i = 0; i < r; ++i) { swap(v[x[i]], v[y[i]]); } ans = findOperations(v); // fill the rest of the operations if needed while (sz(ans) < r) { ans.PB({0, 0}); } vi idx(N); // finding the index of an element a[i] in the array for (int i = 0; i < N; ++i) { idx[s[i]] = i; v[i] = s[i]; // resetting v } for (int i = 0; i < r; ++i) { swap(v[x[i]], v[y[i]]); // performing swap operations } // v ends up being the swapped apples version debug(v); debug(ans); for (int i = 0; i < r; ++i) { // performing the swap operations for Aizhan swap(idx[s[x[i]]], idx[s[y[i]]]); swap(s[x[i]], s[y[i]]); // v[ans[i].ff] and v[ans[i].ss] are the apples corresponding to the plates that need to be flipped // idx[v[ans[i].ff]] and idx[v[ans[i].ss]] are the plates corresponding to the apples in the current array p[i] = idx[v[ans[i].ff]], q[i] = idx[v[ans[i].ss]]; // convert each swap to the index it is currently in and add it to (p, q) swap(idx[s[p[i]]], idx[s[q[i]]]); // flip/update swap(s[p[i]], s[q[i]]); } return r; } void solve() { // testing cases for this algorithm int N, M; int s[100005], x[100005], y[100005], p[100005], q[100005]; cin >> N >> M; for (int i = 0; i < N; ++i) { cin >> s[i]; } for (int i = 0; i < M; ++i) { cin >> x[i] >> y[i]; } vi v(N); for (int i = 0; i < N; ++i) { v[i] = s[i]; } int moves = findSwapPairs(N, s, M, x, y, p, q); cout << moves << '\n'; for (int i = 0; i < moves; ++i) { cout << p[i] << ' ' << q[i] << '\n'; } for (int i = 0; i < moves; ++i) { swap(v[x[i]], v[y[i]]); swap(v[p[i]], v[q[i]]); } cout << "resulting array: \n"; for (int i = 0; i < N; ++i) { cout << v[i] << ' '; } cout << '\n'; } signed main() { // TIME YOURSELF !!! setIO(""); solve(); } // TLE -> TRY NOT USING DEFINE INT LONG LONG // CE -> CHECK LINE 45 // 5000 * 5000 size matrices are kinda big (potential mle) // Do something, start simpler

Compilation message (stderr)

sorting.cpp: In function 'void setIO(const string&)':
sorting.cpp:88:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   88 |     freopen((str + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
sorting.cpp:89:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   89 |     freopen((str + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/bin/ld: /tmp/cccNn1so.o: in function `main':
grader.c:(.text.startup+0x0): multiple definition of `main'; /tmp/cckWOLvr.o:sorting.cpp:(.text.startup+0x0): first defined here
collect2: error: ld returned 1 exit status