1B - Spreadsheet was extremely challenging for me; it took me over 2 hours to get AC, and then when I went to see solutions from red/orange people, it made even less sense. I've seen a bunch of practice solutions to this problem that are basically the following (with minor variation): ~~~~~ #include void g(int t){if(t){g((t-1)/26);putchar(65+(t-1)%26);}} int main(){ int n,x,y; char s[64],*p; for(scanf("%d ",&n);n--;){ gets(s); if(sscanf(s,"%*c%d%*c%d",&x,&y)==2){ g(y); printf("%d\n",x); }else{ for(x=0,p=s;*p>64;++p) x=x*26+*p-64; printf("R%sC%d\n",p,x); } } return 0; } ~~~~~