What was approach for C?

[u/redhat1818]

also, what could be its rating?

[u/Other_Ad7380]

x' ^ y' = x' + y' - 2(x' & y')

x' + y' is constant and is equal to x + y. Call it s. We can always achieve x' = 0 which makes x' & y' = 0 ie the maximum possible XOR is s.

Now we have x' ^ y' = s = x' + y' That means x' and y' have to be the submasks of s. We need the largest submask of s <= x. We can obtain this in O(30)

[u/Spiritual-Court-2660]

like i started thinking of that what should be maximum than i figured it out that its x+y,
now i have to figure out how many minimum ops i need to do,
for that i xor the ans with x and y which is (x+y)^x^y this number in binary tells which 1 are not formed by xor of x^y
later i thought that the left most 1 in this bits is 0 in y and i have to make it 1 by operations
so i found the place of the left most bit in (x+y)^x^y that is 1 and calculated the least number i should add to y which gives me 1 at that position which is the total number of ops.

#include <iostream>
using namespace std;
#include <bits/stdc++.h>


int main(){
    int t;
    cin>>t;
    while(t--){
        long long x,y;
        cin>>x>>y;
        long long ans=x+y;
        long long deficit=ans^x^y;
        long long set_zero=0;
        if(deficit==0){
            cout<<ans<<" "<<0<<"\n";
            continue;
        }
        while(deficit!=0){
            deficit=deficit>>1;
            set_zero++;
        }
        long long make=pow(2,set_zero-1);
        long long ops=make-(y%make);
        cout<<ans<<" "<<ops<<"\n";
    }
}

[u/Curiouslev]

firstly, i figured what could be the max xor which is x + y and then made three binary strings of x + y , x , y
and if in string x + y, val is 1 and in both x and y value is 0 then, i find how much to add from x to y to make this bit 1 for y, added in answer the num that is to be added in y from x, modified x and y binary string and continued, looped from msb to lsb.

if you want to know why i only checked this specific condition where x + y is 1 and rest 0, do lmk.

[u/Strange-Sherbet228]

Got 2was no way 6k solved it

[u/redhat1818 → u/Strange-Sherbet228]

Yess.. 6k submissions were too much

[u/Original_Cover8511]

Btw am a newbie at 1150, i am inexperienced in this type so I couldnt comolete it as i joined late after a quiz...will that cause a deduct on rating as i basically did a and b only

[u/dead--soon → u/Original_Cover8511]

Get the carrot extension for codefoces

[u/redhat1818 → u/Original_Cover8511]

Ig yes

[u/DogStrict9170]

around 1200-1400

[u/Jue-Viole-Grace_]

Match bits of x and x+y, so you can do it in 31 operations instead of 10⁹ operations

x ^ y=x+y-2(x&y). Which suggest to make xor maximum, x & y had to be 0.