Submission #23624301

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Source Code Expand

#include<bits/stdc++.h>
#define rep(i,a,b) for(int i=a;i<b;i++)
#define rrep(i,a,b) for(int i=a;i>=b;i--)
#define fore(i,a) for(auto &i:a)
#define all(x) (x).begin(),(x).end()
//#pragma GCC optimize ("-O3")
using namespace std;
void _main(); int main() { cin.tie(0); ios::sync_with_stdio(false); _main(); }
typedef long long ll; const int inf = INT_MAX / 2; const ll infl = 1LL << 60;
template<class T>bool chmax(T& a, const T& b) { if (a < b) { a = b; return 1; } return 0; }
template<class T>bool chmin(T& a, const T& b) { if (b < a) { a = b; return 1; } return 0; }
//---------------------------------------------------------------------------------------------------
struct UnionFind {
	using T = int;
	const T def = 0;
	T f(T a, T b) { return a + b; }
	//==========================================
    vector<int> par; 
	vector<T> value;
    UnionFind() {}
    UnionFind(int NV) { init(NV); }
	void init(int NV) { par.clear(); rep(i, 0, NV) par.push_back(i); value.resize(NV, 1); }
    void reset() { rep(i, 0, par.size()) par[i] = i; }
	int operator[](int x) {
		if (par[x] == x) return x;
		else {
			int res = operator[](par[x]);
			if (res != par[x]) {
				value[res] = f(value[res], value[par[x]]);
				value[par[x]] = def;
			}
			return par[x] = res;
		}
	}
	// uf(x,y)->y
    void operator()(int x, int y) {
		x = operator[](x); y = operator[](y); 
		if (x != y) {
			value[y] += value[par[x]];
			value[par[x]] = def;
			par[x] = y;
		}
	}
	T getValues(int x) { return value[operator[](x)]; };
};
/*---------------------------------------------------------------------------------------------------
　　　　　　　　　　　 ∧＿∧
　　　　　 ∧＿∧ 　（´<_｀ ）　 Welcome to My Coding Space!
　　　　 （ ´_ゝ`）　/　 ⌒i     @hamayanhamayan0
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　　　 /　　 /￣￣￣￣/　　|
　 ＿_(__ﾆつ/　    ＿/ .| .|＿＿＿＿
　 　　　＼/＿＿＿＿/　（u　⊃
---------------------------------------------------------------------------------------------------*/














int N, A[201010];
//---------------------------------------------------------------------------------------------------
void _main() {
	cin >> N;
	rep(i, 0, N) cin >> A[i];

	UnionFind uf(201010);
	rep(i, 0, N / 2) uf(A[i], A[N - 1 - i]);

	int ans = 0;
	rep(i, 0, 201010) if (uf[i] == i) ans += uf.getValues(i) - 1;
	cout << ans << endl;
}

Submission Info

Compile Error

./Main.cpp: In member function ‘void UnionFind::reset()’:
./Main.cpp:2:33: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::vector<int>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
    2 | #define rep(i,a,b) for(int i=a;i<b;i++)
......
   23 |     void reset() { rep(i, 0, par.size()) par[i] = i; }
      |                        ~~~~~~~~~~~~~~~~
./Main.cpp:23:20: note: in expansion of macro ‘rep’
   23 |     void reset() { rep(i, 0, par.size()) par[i] = i; }
      |                    ^~~

Judge Result