Submission #67005422

---

Source Code Expand

#include <bits/stdc++.h>
using namespace std;
// #define int long long
#define rep(i, j, k) for(int i = (j); i <= (k); i ++)
#define per(i, j, k) for(int i = (j); i >= (k); i --)
#define pb emplace_back
#define fi first
#define se second
using vi = vector<int>;
using pi = pair<int,int>;

template<typename T0, typename T1> bool chmin(T0 &x, const T1 &y){
	if(y < x){x = y; return true;} return false;
}
template<typename T0, typename T1> bool chmax(T0 &x, const T1 &y){
	if(y > x){x = y; return true;} return false;
}

template<typename T> void debug(char *s, T x){
	cerr<< s <<" = "<< x <<endl;
}
template<typename T, typename ...Ar> void debug(char *s, T x, Ar... y){
	int dep = 0;
	while(!(dep == 0 && *s == ',')){
		if(*s == '(') dep++;
		if(*s == ')') dep--;
		cerr << *s++;
	}
	cerr <<" = "<< x <<",";
	debug(s + 1, y...);
}
#define gdb(...) debug((char*)#__VA_ARGS__, __VA_ARGS__)

void solve(){
	int n, m;
	cin >> n >> m;
	vi a(n), b(n);
	for(auto &x:a) cin >> x;
	for(auto &x:b) cin >> x;
	sort(a.begin(), a.end());
	sort(b.begin(), b.end());
	
	auto chk = [&](int p){
		for(int i = p, j = n - 1; i < n; i++, j--){
			if(a[i] + b[j] < m) return false;
		}
		return true;
	};
	
	int l = 0, r = n;
	while(l < r){
		int mid = (l + r) / 2;
		if(chk(mid)){
			r = mid;
		}
		else{
			l = mid + 1;
		}
	}
	int ans = 0;
	for(int i = 0, j = l - 1; i < l; i++, j--){
		chmax(ans, (a[i] + b[j]) % m);
	}
	for(int i = l, j = n - 1; i < n; i++, j--){
		chmax(ans, (a[i] + b[j]) % m);
	}
	cout << ans <<'\n';
}
signed main(){
	#ifdef LOCAL
	freopen(".in","r",stdin);
	freopen(".out","w",stdout);
	#endif
	ios::sync_with_stdio(0);cin.tie(0);
	
	int t;
	cin >> t;
	while(t--){
		solve();
	}
}

Submission Info

Judge Result