Merge pull request #529 from ishikasinha-d/integer-to-roman

Create integer_to_roman.cpp

Author: Saviour1001

Strings/integer_to_roman.cpp

@@ -0,0 +1,45 @@
+// Convert an integer number n to roman number.
+
+#include<bits/stdc++.h>
+#define fl(i,a,b) for(i=a;i<b;i++)
+#define fast ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
+using namespace std;
+typedef long long int ll;
+
+string int_to_roman(ll n)
+{
+   string str="";
+   // store all base values in vector in descending order
+   vector <int > v ={1000,900,500,400,100,90,50,40,10,9,5,4,1};
+
+   // store roman numeral equivalent of each base value using map
+   map <int, string> m ={{1000,"M"}, {900,"CM"},{500,"D"},{400,"CD"},{100,"C"},{90,"XC"},{50,"L"},{40,"XL"},{10,"X"},{9,"IX"},{5,"V"},{4,"IV"},{1,"I"}};
+
+   //now find the largest base value 
+   //dividing the number and repeat the symbol accordingly
+  
+   for(auto x: v)
+   {
+      if(n>0)
+      {
+         int i= n/x;
+         n= n%x;
+         while(i--)
+            str+= m[x];   //repeating the correspoding roman symbol
+      }
+      else
+      return str;
+   }
+   return str;
+}
+
+int main()
+{ 
+   fast;
+
+ll n; cin>>n;
+cout<<int_to_roman(n);
+
+return 0;
+
+}