How do I convert the following C++ code to C code?

#include<stdio.h>
#define NODE 4


int graph[NODE][NODE];
int path[NODE];

void displayCycle() {    //Function to display the cycle obtained
   printf("The Hamilton Cycle : \n");

   for (int i = 0; i < NODE; i++)
      printf(path[i] + "  ");
   cout << path[0] << endl;      //print the first vertex again
}

bool isValid(int v, int k) {
   if (graph [path[k-1]][v] == 0)   //if there is no edge
      return false;

   for (int i = 0; i < k; i++)   //if vertex is already taken, skip that
      if (path[i] == v)
         return false;
   return true;
}

bool cycleFound(int k) {
   if (k == NODE) {             //when all vertices are in the path
      if (graph[path[k-1]][ path[0] ] == 1 )
         return true;
      else
         return false;
   }

   for (int v = 1; v < NODE; v++) {       //for all vertices except starting point
      if (isValid(v,k)) {                //if possible to add v in the path
         path[k] = v;
         if (cycleFound (k+1) == true)
            return true;
         path[k] = -1;               //when k vertex will not in the solution
      }
   }
   return false;
}

bool hamiltonianCycle() {
   for (int i = 0; i < NODE; i++)
      path[i] = -1;
   path[0] = 0;     //first vertex as 0

   if ( cycleFound(1) == false ) {
      cout << "Solution does not exist"<<endl;
      return false;
   }

   displayCycle();
   return true;
}

int main() {
	int i,j;
	cout << "Enter the Graph : " << endl;
	for (i=0;i<NODE;i++){
		for (j=0;j<NODE;j++){
			cout << "Graph G(" << (i+1) << "," << (j+1) << ") = ";
			cin >> graph[i][j];
		}
	}
	cout << endl;
	cout << "The Graph :" << endl;
	for (i=0;i<NODE;i++){
		for (j=0;j<NODE;j++){
			cout << graph [i][j] << "\t";
		}
		cout << endl;
	}
	
	cout << endl;
	
   	hamiltonianCycle();
  }