Euler totient with Bytecode approach

Author: coderick14

euler_totient.cpp

@@ -0,0 +1,53 @@
+#include<iostream>
+#include<vector>
+#include<map>
+using namespace std;
+#define MAX 1000005
+long long phi[MAX];
+void generatePhi()
+{
+
+    phi[1]=1;
+    for(int i=2; i<MAX; i++)
+    {
+        if(phi[i]==0)
+        {
+            phi[i]=i-1;
+            for(int j=(i<<1);j<MAX;j=j+i)
+            {
+                if(!phi[j]) 
+                    phi[j]=j;
+
+                phi[j]=(phi[j]/i)*(i-1);
+            }
+        }
+    }
+}
+
+long long solutions[MAX];
+int main()
+{
+    generatePhi();
+
+
+    for(int i=1; i<MAX; i++)
+    {
+        for(int j=2; i*j<MAX; j++)
+            solutions[i*j] += i*phi[j];
+    }
+
+    for(int i=2; i<MAX; i++)
+    {
+        solutions[i] += solutions[i-1];
+    }
+
+    int t;
+    cin>>t;
+    while(t--)
+    {
+        int n;
+        cin>>n;
+        cout<<solutions[n]<<endl;
+    }
+    return 0;
+}