Submission #482080

#	Time	Username	Problem	Language	Result	Execution time	Memory
482080		Yazan_Alattar	Table Tennis (info1cup20_tabletennis)	C++14	100 / 100	314 ms	33776 KiB

tabletennis

#include <iostream>
#include <fstream>
#include <vector>
#include <cstring>
#include <algorithm>
#include <set>
#include <map>
#include <queue>
#include <list>
#include <utility>
#include <cmath>
#include <numeric>
using namespace std;
typedef long long ll;
#define F first
#define S second
#define pb push_back
#define endl "\n"
#define all(x) x.begin(), x.end()
const int M = 151007;
const ll inf = 1e18;
const ll mod = 1e9 + 7;
const double pi = acos(-1);
const int dx[] = {1, 0, -1, 0}, dy[] = {0, 1, 0, -1};

vector <int> v;
int n, k, a[M];

int solve(int sum)
{
    v.clear();
    int l = 1, r = n + k;
    while(l < r){
        if(v.size() == n) break;
        if(a[l] + a[r] == sum){
            v.pb(l);
            v.pb(r);
            ++l;
            --r;
        }
        else if(a[l] + a[r] > sum) --r;
        else ++l;
    }
    return ((int)v.size() == n);
}

int main()
{
    scanf("%d%d", &n, &k);
    for(int i = 1; i <= n + k; ++i) scanf("%d", &a[i]);
    sort(a + 1, a + n + k + 1);
    int res = 0;
    if(n <= 4 * k){
        for(int i = 1; i <= n + k; ++i){
            for(int j = i + 1; j <= n + k; ++j){
                res = solve(a[i] + a[j]);
                if(res) break;
            }
            if(res) break;
        }
    }
    else{
        map <int,int> cnt;
        for(int i = 1; i <= 2 * k; ++i) for(int j = n - k; j <= n + k; ++j) ++cnt[a[i] + a[j]];
        for(auto i : cnt){
            if(i.S >= k){
                res = solve(i.F);
                if(res) break;
            }
        }
    }
    sort(all(v));
    for(auto i : v) printf("%d ", a[i]);
    printf("\n");
    return 0;
}
// Don't forget special cases. (n = 1?)
// Look for the constraints. (Runtime array? overflow?)

Compilation message (stderr)

tabletennis.cpp: In function 'int solve(int)':
tabletennis.cpp:34:21: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   34 |         if(v.size() == n) break;
      |            ~~~~~~~~~^~~~
tabletennis.cpp: In function 'int main()':
tabletennis.cpp:49:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   49 |     scanf("%d%d", &n, &k);
      |     ~~~~~^~~~~~~~~~~~~~~~
tabletennis.cpp:50:42: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   50 |     for(int i = 1; i <= n + k; ++i) scanf("%d", &a[i]);
      |                                     ~~~~~^~~~~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 9 / 9
• Subtask 3: 14 / 14
• Subtask 4: 15 / 15
• Subtask 5: 9 / 9
• Subtask 6: 14 / 14
• Subtask 7: 15 / 15
• Subtask 8: 13 / 13