Submission #528664

#	Time	Username	Problem	Language	Result	Execution time	Memory
528664		happypotato	Arranging Shoes (IOI19_shoes)	C++17	15 / 100	27 ms	1860 KiB

shoes

#include "shoes.h"
#include <bits/stdc++.h>
#define ll long long
using namespace std;
const int mxN = 2e5 + 1;
int seg[4 * mxN];
int n;
void update(int tar, int l = 1, int r = n, int idx = 1) {
    if (l == r) {
        seg[idx] ^= 1;
        return;
    }
    int mid = (l + r) >> 1;
    if (tar <= mid) update(tar, l, mid, (idx << 1));
    else update(tar, mid + 1, r, (idx << 1) + 1);
    seg[idx] = seg[(idx << 1)] + seg[(idx << 1) + 1];
    return;
}
int query(int tarl, int tarr, int l = 1, int r = n, int idx = 1) {
    if (tarl > tarr) return 0;
    if (tarl <= l && r <= tarr) return seg[idx];
    else if (tarr < l || r < tarl) return 0;
    int mid = (l + r) >> 1;
    return query(tarl, min(tarr, mid), l, mid, (idx << 1)) + query(max(tarl, mid + 1), tarr, mid + 1, r, (idx << 1) + 1);
}
long long st1(vector<int> &s) {
    if (s[0] == -1 && s[1] == 1) return 0;
    else if (s[0] == 1 && s[1] == -1) return 1;
    else {
        while (true) continue;
    }
}
long long st2(vector<int> &s) {
    return -1;
}
long long st3(vector<int> &s) {
    return -1;
}
long long st4(vector<int> &s) {
    long long n = s.size() / 2;
    n = (n - 1) * n / 2;
    return n;
}
long long count_swaps(vector<int> s) {
    n = s.size();
    if (n == 1) return st1(s);
    // else if (n <= 8) return st2(s);
    // bool ckst3 = true;
    // for (int i = 1; i < n; i++) {
    //     if (abs(s[0]) != abs(s[i])) {
    //         ckst3 = false;
    //         break;
    //     }
    // }
    // if (ckst3) return st3(s);
    bool ckst4 = true;
    for (int i = 0; i < n / 2; i++) {
        if (s[i] + s[i + n] != 0 || s[i] > 0) {
            ckst4 = false;
            break;
        }
    }
    if (ckst4) return st4(s);
}

Compilation message (stderr)

shoes.cpp: In function 'long long int count_swaps(std::vector<int>)':
shoes.cpp:64:1: warning: control reaches end of non-void function [-Wreturn-type]
   64 | }
      | ^

• Subtask 1: 0 / 10
• Subtask 2: 0 / 20
• Subtask 3: 0 / 20
• Subtask 4: 15 / 15
• Subtask 5: 0 / 20
• Subtask 6: 0 / 15