pigeonhole

Author: ivorynoise

GRAYSC-d.cpp

@@ -0,0 +1,38 @@
+//codechef-pigeonhole
+#include <bits/stdc++.h>
+using namespace std;
+typedef unsigned long long ll;
+typedef vector<ll> vi;
+typedef vector<vi> vvi;
+const int mod = 1000000007;
+const int sze = 100010;
+void printMat(vvi& a) {for (int i = 0; i < a.size(); ++i) {for (int j = 0; j < a[0].size(); ++j)cout << a[i][j] << " ";} cout << "\n";}
+int main() {
+	ll arr[100000];
+	int n;
+	cin >> n;
+	for (int i = 0 ; i < n; ++i) {
+		cin >> arr[i];
+	}
+
+	if (n >= 130) {
+		cout << "Yes";
+		return 0;
+	}
+
+	sort(arr, arr + n);
+	for(int i = 0; i < n-3; ++i){
+		for(int j = i + 1; j < n -2; ++j ){
+			for(int k = j + 1; k < n - 1; ++k){
+				ll toFind = arr[i] ^ arr[j] ^ arr[k];
+				if (binary_search(arr + k + 1, arr + n, toFind)) {
+					//returns true or false
+					cout << "Yes";
+					return 0;
+				}
+			}
+		}
+	}
+
+	cout << "No";
+}