Add Codeforces Code

CodeForces/Arranging Cats.cpp

@@ -0,0 +1,25 @@
+#include<iostream>
+#include<string>
+#include<algorithm>
+using namespace std;
+
+int t;
+int main()
+{
+    cin >> t;
+    while(t -- )
+    {
+        int n;
+        cin >> n;
+        string s1, s2;
+        cin >> s1 >> s2;
+        int x = 0, y = 0;
+        for(int i = 0; i < n; i ++ )
+        {
+            if(s1[i] == '1' && s2[i] == '0') x ++ ;
+            if(s1[i] == '0' && s2[i] == '1') y ++ ;
+        }
+        cout << max(x, y) << endl;
+    }
+    return 0;
+}

CodeForces/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;
+}

CodeForces/README.md

@@ -0,0 +1 @@
+# CF题不多，后面会做的！！！！！