Submission #280073

#	Time	Username	Problem	Language	Result	Execution time	Memory
280073		ec1117	Arranging Shoes (IOI19_shoes)	C++17	Compilation error	0 ms	0 KiB

shoes

/**
 * Description: range sum queries and point updates for $D$ dimensions
 * Source: https://codeforces.com/blog/entry/64914
 * Verification: SPOJ matsum
 * Usage: \texttt{BIT<int,10,10>} gives 2D BIT
 * Time: O((\log N)^D)
 */


#include "bits/stdc++.h"
#include "shoes.h"
using namespace std;

typedef long long ll;
typedef vector<int> vi;
typedef pair<int,int> pi;

#define pb push_back
#define mp make_pair
#define sz(v) ((int)(v).size())

const int MAXN=100000;

struct bit{
    int tree[MAXN];
    void add(int x, int v){
        for(int i=x; i<MAXN; i+=i&-i) tree[i] += v;
    }
    int query(int x){
        int ret = 0;
        for(int i=x; i; i-=i&-i) ret += tree[i];
        return ret;
    }
}bit;


int n;
vector<pi> order[MAXN];
vector<pi> calc;
ll count_swaps(int s[]){
    ll ret=0;
    for(int i=0;i<sizeof(s);i++)
        order[abs(s[i])].push_back(mp(s[i],i));
    for(int i=0;i<MAXN;i++){
        sort(order[i].begin(), order[i].end());
        for(int j=0;j<order[i].size()/2;j++){
            int l = order[i][j].second;
            int r = order[i][j + sz(order[i])/2].second;
            if(l>r) {
                ret++;
                swap(l,r);
            }
            calc.push_back(mp(l+1,r+1));
        }
    }
    sort(calc.begin(),calc.end());
    for(pi x:calc){
        int range=bit.query(x.second)-bit.query(x.first);
        ret+=x.second-x.first-range;
        bit.add(x.second,-1);
        bit.add(x.first,-1);
    }
    return ret;
}

Compilation message (stderr)

shoes.cpp: In function 'll count_swaps(int*)':
shoes.cpp:42:27: warning: 'sizeof' on array function parameter 's' will return size of 'int*' [-Wsizeof-array-argument]
   42 |     for(int i=0;i<sizeof(s);i++)
      |                           ^
shoes.cpp:40:20: note: declared here
   40 | ll count_swaps(int s[]){
      |                ~~~~^~~
shoes.cpp:42:18: warning: comparison of integer expressions of different signedness: 'int' and 'long unsigned int' [-Wsign-compare]
   42 |     for(int i=0;i<sizeof(s);i++)
      |                 ~^~~~~~~~~~
shoes.cpp:46:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   46 |         for(int j=0;j<order[i].size()/2;j++){
      |                     ~^~~~~~~~~~~~~~~~~~
/tmp/ccinhkQ2.o: In function `main':
grader.cpp:(.text.startup+0x27a): undefined reference to `count_swaps(std::vector<int, std::allocator<int> >)'
collect2: error: ld returned 1 exit status