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#! /usr/bin/env gforth
\ Challenge 091
\
\ TASK #2: Jump Game
\
\ You are given an array of positive numbers @N, where value at each index
\ determines how far you are allowed to jump further. Write a script to decide
\ if you can jump to the last index. Print 1 if you are able to reach the last
\ index otherwise 0.
0 VALUE tbl-size \ save table size
\ collect_args, append them to heap
: collect_args ( -- )
0 TO tbl-size
BEGIN NEXT-ARG DUP 0> WHILE
S>NUMBER? 0= THROW DROP ,
tbl-size 1+ TO tbl-size
REPEAT
;
CREATE tbl
collect_args
\ run the table
: run ( -- f )
0 ( pos )
BEGIN
DUP tbl-size 1- = IF \ pos = tbl-size - 1
DROP 1 EXIT \ found end
ELSE
DUP tbl-size 1- > IF \ pos > tbl-size - 1
DROP 0 EXIT \ behond end
THEN
THEN
DUP CELLS tbl + @ ( pos tbl[pos] )
DUP 0= IF \ tbl[pos] = 0
DROP 0 EXIT \ no solution
THEN
+
AGAIN
;
run . CR BYE
|
