Submission #583488

#	Time	Username	Problem	Language	Result	Execution time	Memory
583488		lcj	Arranging Shoes (IOI19_shoes)	C++17	0 / 100	1130 ms	627276 KiB

shoes

#include <bits/stdc++.h>

#define LSOne(s) ((s) & -(s))
using namespace std;

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

struct FenwickTree {
    vector<ll> ft;
    FenwickTree(int n) : ft(n+1) {}
    ll rsq(int i) {
        ll su = 0;
        for (; i > 0; i -= LSOne(i)) {
            su += ft[i];
        }
    }
    ll rsq(int i, int j) {
        return rsq(j)-rsq(i-1);
    }
    void update(int i, int dv) {
        for (; i < (int)ft.size(); i += LSOne(i)) {
            ft[i] += dv;
        }
    }
};

ll count_swaps(std::vector<int> s) {
    FenwickTree ft(s.size());
    map<int, int> open;
    int csum = 0;
    for (int i = 0; i < s.size(); i++)
    {
        if (open.find(-s[i]) != open.end()) {
            csum += i-open[-s[i]]-1 + (s[i] < 0) - ft.rsq(open[-s[i]]+1, i+1);
            ft.update(i, 1);
            open.erase(-s[i]);
        }
        else {
            open[s[i]] = i;
        }
    }
    return csum;
}

Compilation message (stderr)

shoes.cpp: In member function 'll FenwickTree::rsq(int)':
shoes.cpp:18:5: warning: no return statement in function returning non-void [-Wreturn-type]
   18 |     }
      |     ^
shoes.cpp: In function 'll count_swaps(std::vector<int>)':
shoes.cpp:33:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   33 |     for (int i = 0; i < s.size(); i++)
      |                     ~~^~~~~~~~~~

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