SPOJ code for PALIN

PALIN.py

#AnubhavBalodhi, SPOJ, PALIN, 16/08/2024


def nextPalin(num :str ) -> str:


    odd_or_not = len(num)%2
    h_len = len(num)//2
    full = [int(c) for c in num]
    
    first_half = [int(c) for c in num[:h_len]] 
    secnd_half = [int(c) for c in num[h_len+odd_or_not:]] 
    rev_first_half = list(reversed(first_half))
    
    def makePalin() :
        # iff the PALIN is of ODD length
        if odd_or_not:
            middle = len(num)//2
            m=full[middle] 
            if m == 9 :
                m=0
            return first_half + [m] + rev_first_half
        else:
            return first_half + rev_first_half
        
    i=0

    palin=makePalin()
    while palin <= full and i < h_len:
        diff = rev_first_half[i] - secnd_half[i]
        if diff > 0 :
            break
        k =  rev_first_half[i]+1 
        rev_first_half[i]=k
        first_half[h_len-i-1]=k
        i += 1
        palin = makePalin()
        print(f"PALIN {first_half=} {rev_first_half=} | {secnd_half=},{rev_first_half=} | {palin=} |")
    
    return palin
        


def main():
    t=int(input().strip())
    
    for i in range(t):
        n = input().strip()
        print(nextPalin(n))

main()