Mismatched Socks
12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576777879808182838485868788
#include <bits/stdc++.h>
using namespace std;
// type
#define int long long
typedef long long ll;
typedef long double ld;
// loop
//#define For(i, l, r, x) for (int i = l; i < r; i+=x)
//#define ForE(i, l, r, x) for (int i = l; i <= r; i+=x)
//#define Ford(i, r, l) for (int i = r; i > l; i--)
//#define FordE(i, r, l) for (int i = r; i >= l; i--)
//#define Fora(i, a) for (auto i : a)
// I/O
#define openfile(file) freopen(file".in", "r", stdin); freopen(file".out", "w", stdout);
#define testinput(file) freopen(file".txt", "r", stdin);
#define FAST_IO std::ios::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
//#define PrintV(a) Fora(ii, a) cout << ii << ' '; cout << rl;
//#define PrintVl(a) Fora(ii, a) cout << ii << rl;
//#define PrintA(a, l, r) for (int ii = l; ii <= r; ii++) cout << a[ii] << ' '; cout << rl;
//#define PrintAl(a, l, r) for (int ii = l; ii <= r; ii++) cout << a[ii] << rl;
//#define Ptest(x) return cout << x, 0;
#define setpre(n) fixed << setprecision(n)
// pair
#define F first
#define S second
#define pii pair<int, int>
#define pll pair<ll, ll>
#define pdd pair<ld, ld>
// vector & !!?(string)
#define eb emplace_back
#define pb push_back
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define sz(a) a.size()
#define len(a) a.length()
// geometry calc
#define pi acos(-1.0)
#define g_sin(a) sin(a*pi/180)
#define g_cos(a) cos(a*pi/180)
#define g_tan(a) tan(a*pi/180)
// set val
#define ms0(a) memset(a, 0, sizeof(a));
#define ms1(a) memset(a, 1, sizeof(a));
#define msn1(a) memset(a, -1, sizeof(a));
#define msinf(a) memset(a, 0x3f3f3f, sizeof(a));
// constant
const int mod1 = 998244353, mod = 1e9+7;
const int MAXN = 1000005, MAXM = 200010;
// code
void Solve(){
int n; cin >> n;
vector<int> a(n);
for (int i = 0; i < n; i++)
cin >> a[i];
if (n == 1){
cout << 0;
return ;
}
sort(all(a));
int temp = 0, ans = 0;
for (int i = 0; i < n - 2; i++){
int k = min(a[n-1] - a[n-2], a[i]);
ans += k;
a[n-1] -= k;
a[i] -= k;
if (a[i]) break;
}
ans += a[n-2];
for (int i = 0; i < n - 2; i++){
temp += a[i];
}
ans += temp / 2;
cout << ans;
}
signed main(){
FAST_IO;
int TC = 1;
//cin >> TC;
while(TC--) Solve();
cerr << "Time elapsed : " << 1.0 * clock() / CLOCKS_PER_SEC << " sec \n";
return 0;
}
Cpp
INFO