reversed-c, 80 bytes

Result

WA

Duration

736ms

Code [DL]

{؛1+()ɹɐɥɔʇǝƃ=X((0:,0,+W/X¿W⅋X)ɹɐɥɔʇnd؛X=W؛)ɹoɟ}(W'X)uıɐɯ

Disassembly

main(X,M){for(;M=X;putchar(X&M?X/M+'0':0))X=getchar()+1;}

stdin

80930868492039173451976129876543210296012809416425214545798757365171301234567896518164850124107134538

stdout

i01001010100110101101000110000000001100111010010010011011100010100101011111111100010101001110010111010

stderr

/tmp/code.c:1:1: warning: return type defaults to 'int' [-Wimplicit-int]
 main(X,M){for(;M=X;putchar(X&M?X/M+'0':0))X=getchar()+1;}
 ^~~~
/tmp/code.c: In function 'main':
/tmp/code.c:1:1: warning: type of 'X' defaults to 'int' [-Wimplicit-int]
/tmp/code.c:1:1: warning: type of 'M' defaults to 'int' [-Wimplicit-int]
/tmp/code.c:1:1: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
/tmp/code.c:1:20: warning: implicit declaration of function 'putchar' [-Wimplicit-function-declaration]
 main(X,M){for(;M=X;putchar(X&M?X/M+'0':0))X=getchar()+1;}
                    ^~~~~~~
/tmp/code.c:1:45: warning: implicit declaration of function 'getchar' [-Wimplicit-function-declaration]
 main(X,M){for(;M=X;putchar(X&M?X/M+'0':0))X=getchar()+1;}
                                             ^~~~~~~

strace