Submission #64295833

---

Source Code Expand

#include <bits/stdc++.h>
using namespace std;
#define rep(i,l,r) for (int i = (l); i <= (r); i++)
#define per(i,r,l) for (int i = (r); i >= (l); i--)
#define pb push_back
#define eb emplace_back
#define mp make_pair
#define all(x) (x).begin(),(x).end()
#define fi first
#define se second
#define SZ(x) ((int)(x).size())
#define maxn(a, b) a = max(a, b)
#define minn(a, b) a = min(a, b)
typedef vector<int> VI;
typedef long long ll;
typedef pair<int,int> PII;
typedef double db;
const ll mod = 998244353;
mt19937 gen(random_device{}());
ll rp(ll a,ll b) {ll res=1%mod;a%=mod; assert(b>=0); for(;b;b>>=1){if(b&1)res=res*a%mod;a=a*a%mod;}return res;}
ll gcd(ll a,ll b) { return b?gcd(b,a%b):a;}

const int N = 400100;
int n;
int a[N];
bool no[N];
set<PII> st;

void solve() {
	// init();
	scanf("%d", &n);
	st.clear();
	rep(i,1,n) no[i] = false;
	rep(i,1,2 * n) {
		scanf("%d", &a[i]);
		if (i > 1 && a[i] == a[i - 1]) no[a[i]] = true;
	}
	int ans = 0;
	rep(i,3,2 * n) {
		if (a[i] != a[i - 1] && !no[a[i]] && !no[a[i - 1]]) {
			if (st.count(mp(a[i], a[i - 1]))) {
				ans++;
			}
		}
		if (a[i - 1] != a[i - 2]) {
			st.insert(mp(a[i - 1], a[i - 2]));
			st.insert(mp(a[i - 2], a[i - 1]));
		}
	}
	printf("%d\n", ans);
}

int main() {
	int T;
	scanf("%d", &T);
	while (T--)
		solve();
	return 0;
}

Submission Info

Compile Error

Main.cpp: In function ‘void solve()’:
Main.cpp:31:14: warning: ignoring return value of ‘int scanf(const char*, ...)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
   31 |         scanf("%d", &n);
      |         ~~~~~^~~~~~~~~~
Main.cpp:35:22: warning: ignoring return value of ‘int scanf(const char*, ...)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
   35 |                 scanf("%d", &a[i]);
      |                 ~~~~~^~~~~~~~~~~~~
Main.cpp: In function ‘int main()’:
Main.cpp:55:14: warning: ignoring return value of ‘int scanf(const char*, ...)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
   55 |         scanf("%d", &T);
      |         ~~~~~^~~~~~~~~~

Judge Result