JAVA code

public static long flippingBits(long n) {
// Write your code here

return n ^ 0xFFFFFFFFL; }

c++ solution. The key is that NOT operation on bits does the 'flipping'. And since we operate on unsigned positive ints, gotta add 2 times INTMAX+1 to avoid negative numbers.

long flippingBits(long n) {
    
    return ~n+2l*INT32_MAX+2;
}

C makes this trivial using the XOR operator: return(UINT32_MAX^n);

C++ Solution

long flippingBits(long n) {
    return ~((unsigned)n);
}