AND Reachability DP Problem

#61

Magar main() function ke andar ese define nai karte hai agr static array ko main() ke andar initialize kr rhe hai tab …

#62

global scope mein allow nahi hota aisa na ,waha const banana mandatory hain.

in main it is allowed.
but then also static array ka size nahi badal skate

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#63

ans|=(((a[y]>>j) & 1) && go[x][j]<=y);

Bhaiya, iss condition meh go[x][j]<=(y-x) esa hona tha na…

#64

no…
we are iterting to all set bit position of y (say j).
and then we are checking what is the smallest index that we can reach from x whose jth bit position is set.

if we get any index which is <=y then we can clearly reach to y.(first we reach to that smallest index and because it (value at that index) has atleast one bit common with a[y] we can reach to y from there using that common bit)
answer will be true.

((a[y]>>j) & 1) <- this is checking jth bit is set or not && go[x][j]<=y <- this is checking whether smallest index reachable from x (whose value jth bit is set )is less than equal to y or not.

#65

Accha…toh agar mujhe smallest index nikal na rahta between x and y tab meh esa likhta…

for(int j=0;j<=19;j++){
    if((a[y]>>j) & 1)
        ans=min(ans,go[x][j]);
    }
#66

ha correct. . . . . . . .

#67

Bhaiya, pahle CB wala code apko samjh aya tha kya?

#68

maine wo dekha hi nahi hai…
mujhe erichto ka logic kaafi logical aur simple laga tha isliye mein usi se solve kiya.

#69

Bhaiya, errichto wala bhi thoda alag hai…maine same bataya tha codeforces ke editorial se magr thoda alag hai…

#70

dont know mujhe hint mil gya tha approach ki wahi kaafi tha.

#71 
for(int i=n-1;i>=0;i--){

        for(int j=0;j<=19;j++){

            go[i][j]=n;

        }

Bhaiya, for loop ke andar har baar go[i][j] ko n se initialize karne ka kya mtlb hai…maine toh ekbaar pahle hi initialize kar diye the…magr fir se same chiz…samjh nai aya yeh

#72

ha intitially max value n ya any number > n se intitilaise kar rahe hai . to indicate that as of now we cannot reach anywhere.

but later in other loop
we are updating these value
dp[i][j]=min(dp[i][j],somehting else) this will update its value

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#73

Bhaiya, esa agar hard question rha codeforces peh tab toh contest meh participate karna, bhul jana hi behtar hai…

#74

no bro aise nahi karna chaiye , participate reguraly and focus on learning instead of rating or anything else .

baaki ye problem tough to thi (div1 c ka matlab hai div2 ka f o my gaaaad)
no doubt khtrnak sawal tha

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#75

Bhaiya, aap kese div(1,2,3…) and (a,b,c…) se question ko judge kar rhe hai? Thoda mujhe bhi batayiyega, inn sab ka question ke sath kya taluk hai…

Itna pata tha ki div1 A hard hai sabse jada…kyun ki maine Nauuo and Cards ka problem kara tha jo mujhe 12 din laga samjh ne meh…

#76

div2 ki difficulty c/d div1 ke a ke barabr hoti hai.
usi hisab se e-f ke equivalent bol raha tha.

#77

Toh fir, beginner ko pahle div1 ya div 2 karna chahiye?

#78

div 2 n div 3. . . . . . …

#79

Esa hai kya difficulty level:

Div 1>Div 2>Div 3

And, A<B<C<D<E<F (in every Div)

#80

ha …
baaki abhi ye doubt to clear ho gya na?