initial commit

122B Lucky Substring/122B.cpp

@@ -0,0 +1,30 @@
+#include<bits/stdc++.h>
+using namespace std;
+using ll = long long;
+
+void solve()
+{
+    int c4=0,c7=0;
+    string s;
+    cin>>s;
+    for(int i=0; i<s.size(); ++i)
+    {
+        if(s[i]=='4') c4++;
+        else if(s[i]=='7') c7++;
+    }
+    if(c4==0 && c7==0) cout<<"-1"<<endl;
+    else if(c4>c7) cout<<"4"<<endl;
+    else if(c7>c4) cout<<"7"<<endl;
+    else if(c7==c4) cout<<"4"<<endl;
+}
+
+int main()
+{
+    ios_base::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    int TC = 1;
+    //cin >> TC;
+    //cin.ignore();
+    while (TC--) solve();
+}