diff --git a/codeforces/solo-problems/1922B_Forming_Triangles.cpp b/codeforces/solo-problems/1922B_Forming_Triangles.cpp
new file mode 100644
index 0000000..b363332
--- /dev/null
+++ b/codeforces/solo-problems/1922B_Forming_Triangles.cpp
@@ -0,0 +1,19 @@
+#include<iostream>
+using namespace std;
+
+long long t, n, a[300005];
+long long cnt[300005], s[300005], ans;
+int main(){
+	ios::sync_with_stdio(0);
+	cin >> t;
+	while(t -- ){
+		cin >> n;
+		ans = 0;
+		for(int i = 0; i <= n; i ++ ) cnt[i] = s[i] = 0;
+		for(int i = 1; i <= n; i ++ ) cin >> a[i], cnt[a[i]] ++ ;
+		for(int i = 0; i <= n; i ++ ) ans += cnt[i] * (cnt[i] - 1) * (cnt[i] - 2) / 6, s[i] = (i == 0 ? 0 : s[i - 1]) + cnt[i];
+		for(int i = 1; i <= n; i ++ ) ans += cnt[i] * (cnt[i] - 1) / 2 * s[i-1];
+		cout << ans << "\n";
+	}
+	return 0;
+}