c-gcc, 117 bytes

Result

WA

Duration

619ms

Code [DL]

main(){char i[101];b,c,d;for(b=gets(i),d=b;b;b--)if(i[d-b]-48>9)for(c=1<i[d-b-1]-48<=9?:1;c;c--)printf("%c",i[d-b]);}

stdin

w7w6b2b4c6d6q2e5q9t2v3wgvk8b3m9p9m4r8n4c4w8l7kfo4w4s7y2c4p9ad8m7x8v2g8f8h9s3j6e2p5u4z8r9i5x7a4

stdout

stderr

/tmp/code.c:1:1: warning: return type defaults to 'int' [-Wimplicit-int]
 main(){char i[101];b,c,d;for(b=gets(i),d=b;b;b--)if(i[d-b]-48>9)for(c=1<i[d-b-1]-48<=9?:1;c;c--)printf("%c",i[d-b]);}
 ^~~~
/tmp/code.c: In function 'main':
/tmp/code.c:1:20: error: 'b' undeclared (first use in this function)
 main(){char i[101];b,c,d;for(b=gets(i),d=b;b;b--)if(i[d-b]-48>9)for(c=1<i[d-b-1]-48<=9?:1;c;c--)printf("%c",i[d-b]);}
                    ^
/tmp/code.c:1:20: note: each undeclared identifier is reported only once for each function it appears in
/tmp/code.c:1:22: error: 'c' undeclared (first use in this function)
 main(){char i[101];b,c,d;for(b=gets(i),d=b;b;b--)if(i[d-b]-48>9)for(c=1<i[d-b-1]-48<=9?:1;c;c--)printf("%c",i[d-b]);}
                      ^
/tmp/code.c:1:21: warning: left-hand operand of comma expression has no effect [-Wunused-value]
 main(){char i[101];b,c,d;for(b=gets(i),d=b;b;b--)if(i[d-b]-48>9)for(c=1<i[d-b-1]-48<=9?:1;c;c--)printf("%c",i[d-b]);}
                     ^
/tmp/code.c:1:24: error: 'd' undeclared (first use in this function)
 main(){char i[101];b,c,d;for(b=gets(i),d=b;b;b--)if(i[d-b]-48>9)for(c=1<i[d-b-1]-48<=9?:1;c;c--)printf("%c",i[d-b]);}
                        ^
/tmp/code.c:1:23: warning: left-hand operand of comma expression has no effect [-Wunused-value]
 main(){char i[101];b,c,d;for(b=gets(i),d=b;b;b--)if(i[d-b]-48>9)for(c=1<i[d-b-1]-48<=9?:1;c;c--)printf("%c",i[d-b]);}
                       ^
/tmp/code.c:1:32: warning: implicit declaration of function 'gets' [-Wimplicit-function-declaration]
 main(){char i[101];b,c,d;for(b=gets(i),d=b;b;b--)if(i[d-b]-48>9)for(c=1<i[d-b-1]-48<=9?:1;c;c--)printf("%c",i[d-b]);}
                                ^~~~
/tmp/code.c:1:39: warning: left-hand operand of comma expression has no effect [-Wunused-value]
 main(){char i[101];b,c,d;for(b=gets(i),d=b;b;b--)if(i[d-b]-48>9)for(c=1<i[d-b-1]-48<=9?:1;c;c--)printf("%c",i[d-b]);}
                                       ^
/tmp/code.c:1:97: warning: implicit declaration of function 'printf' [-Wimplicit-function-declaration]
 main(){char i[101];b,c,d;for(b=gets(i),d=b;b;b--)if(i[d-b]-48>9)for(c=1<i[d-b-1]-48<=9?:1;c;c--)printf("%c",i[d-b]);}
                                                                                                 ^~~~~~
/tmp/code.c:1:97: warning: incompatible implicit declaration of built-in function 'printf'
/tmp/code.c:1:97: note: include '<stdio.h>' or provide a declaration of 'printf'
+#include <stdio.h>
 main(){char i[101];b,c,d;for(b=gets(i),d=b;b;b--)if(i[d-b]-48>9)for(c=1<i[d-b-1]-48<=9?:1;c;c--)printf("%c",i[d-b]);}
                                                                                                 ^~~~~~
/root/script: line 7: /tmp/code: not found
rm: can't remove '/tmp/code': No such file or directory

strace