memset(a,0,sizeof(a))

#include <bits/stdc++.h> 
using namespace std; 
   
int main() 
{ 
    int a[5]; 
   
    // all elements of A are zero 
    memset(a, 0, sizeof(a)); 
    for (int i = 0; i < 5; i++) 
        cout << a[i] << " "; 
    cout << endl; 
   
    // all elements of A are -1 
    memset(a, -1, sizeof(a)); 
    for (int i = 0; i < 5; i++) 
        cout << a[i] << " "; 
    cout << endl; 
   
    // Would not work 
    memset(a, 5, sizeof(a)); // WRONG 
    for (int i = 0; i < 5; i++) 
        cout << a[i] << " "; 
} 

0 0 0 0 0 
-1 -1 -1 -1 -1 
84215045 84215045 84215045 84215045 84215045