Code solution for Redmart's coding challenge see http://geeks.redmart.com/2015/01/07/skiing-in-singapore-a-coding-diversion/

redmart_challenge.py

import sys

def create_map(filename):
    f = open(filename, "r")
    lines = f.readlines()

    rows = int(lines[0].split()[0])
    cols = int(lines[0].split()[1])

    skimap = [[int(c) for c in lines[i].split()] for i in range(1,len(lines))]

    return skimap, rows, cols


def go_north(skimap,lengths,levels,rows,cols,r,c):
    return get_lg_lvl(skimap,lengths,levels,rows,cols,r-1,c)


def go_east(skimap,lengths,levels,rows,cols,r,c):
    return get_lg_lvl(skimap,lengths,levels,rows,cols,r,c+1)


def go_south(skimap,lengths,levels,rows,cols,r,c):
    return get_lg_lvl(skimap,lengths,levels,rows,cols,r+1,c)


def go_west(skimap,lengths,levels,rows,cols,r,c):
    return get_lg_lvl(skimap,lengths,levels,rows,cols,r,c-1)


def get_lg_lvl(skimap,lengths,levels,rows,cols,r,c):

    ''' if current cell length and level have been calculated, retrieve and return from memory '''
    if lengths[r][c] != 0:
        return skimap,lengths,levels,rows,cols,lengths[r][c],levels[r][c]

    ''' initialize local memory storage for comparison later '''
    local_lgs = [0 for x in range(4)]
    local_lvls = [0 for x in range(4)]

    curr_height = skimap[r][c]

    LOCAL_NORTH = 0
    LOCAL_EAST = 1
    LOCAL_SOUTH = 2
    LOCAL_WEST = 3

    ''' for each direction, if hit the boundary, length is 1 and level is 0 '''
    ''' if current cell level is greater than adjacent cell level, retrieve the max length and step of the adjacent cell '''
    #north
    if r-1 <= 0:
        local_lgs[LOCAL_NORTH] = 1
        local_lvls[LOCAL_NORTH] = 0
    else:
        north_height = skimap[r-1][c]
        if curr_height > north_height:
            skimap,lengths,levels,rows,cols,local_lgs[LOCAL_NORTH],local_lvls[LOCAL_NORTH] = go_north(skimap,lengths,levels,rows,cols,r,c)
            local_lgs[LOCAL_NORTH] = local_lgs[LOCAL_NORTH] + 1
            local_lvls[LOCAL_NORTH] = local_lvls[LOCAL_NORTH] + (curr_height - north_height)
        else:
            local_lgs[LOCAL_NORTH] = 1
            local_lvls[LOCAL_NORTH] = 0

    #east
    if c+1 >= cols:
        local_lgs[LOCAL_EAST] = 1
        local_lvls[LOCAL_EAST] = 0
    else:
        east_height = skimap[r][c+1]
        if curr_height > east_height:
            skimap,lengths,levels,rows,cols,local_lgs[LOCAL_EAST],local_lvls[LOCAL_EAST] = go_east(skimap,lengths,levels,rows,cols,r,c)
            local_lgs[LOCAL_EAST] = local_lgs[LOCAL_EAST] + 1
            local_lvls[LOCAL_EAST] = local_lvls[LOCAL_EAST] + (curr_height - east_height)
        else:
            local_lgs[LOCAL_EAST] = 1
            local_lvls[LOCAL_EAST] = 0

    #south
    if r+1 >= rows:
        local_lgs[LOCAL_SOUTH] = 1
        local_lvls[LOCAL_SOUTH] = 0
    else:
        south_height = skimap[r+1][c]
        if curr_height > south_height:
            skimap,lengths,levels,rows,cols,local_lgs[LOCAL_SOUTH],local_lvls[LOCAL_SOUTH] = go_south(skimap,lengths,levels,rows,cols,r,c)
            local_lgs[LOCAL_SOUTH] = local_lgs[LOCAL_SOUTH] + 1
            local_lvls[LOCAL_SOUTH] = local_lvls[LOCAL_SOUTH] + (curr_height - south_height)
        else:
            local_lgs[LOCAL_SOUTH] = 1
            local_lvls[LOCAL_SOUTH] = 0

    #west
    if c-1 <= 0:
        local_lgs[LOCAL_WEST] = 1
        local_lvls[LOCAL_WEST] = 0
    else:
        west_height = skimap[r][c-1]
        if curr_height > west_height:
            skimap,lengths,levels,rows,cols,local_lgs[LOCAL_WEST],local_lvls[LOCAL_WEST] = go_west(skimap,lengths,levels,rows,cols,r,c)
            local_lgs[LOCAL_WEST] = local_lgs[LOCAL_WEST] + 1
            local_lvls[LOCAL_WEST] = local_lvls[LOCAL_WEST] + (curr_height - west_height)
        else:
            local_lgs[LOCAL_WEST] = 1
            local_lvls[LOCAL_WEST] = 0

    ''' get the max length from the 4 adjacent cells, if current length equals max length, compare current level with max level '''
    curr_max_lg = 1
    curr_max_lvl = 0

    for i in range(len(local_lvls)):
        lg = local_lgs[i]
        lvl = local_lvls[i]
        if lg > curr_max_lg:
            curr_max_lg = lg
            curr_max_lvl = lvl
        elif lg == curr_max_lg:
            if lvl > curr_max_lvl:
                curr_max_lg = lg
                curr_max_lvl = lvl

    ''' store the current max length and level in memory '''
    levels[r][c] = curr_max_lvl
    lengths[r][c] = curr_max_lg

    return skimap,lengths,levels,rows,cols,curr_max_lg,curr_max_lvl


if __name__ == '__main__':
    if len(sys.argv) != 2:
        print "try 'python challenge.py <filename>'"
        sys.exit()

    filename = sys.argv[1]

    skimap, rows, cols = create_map(filename)

    lengths = [[0 for x in range(cols)] for y in range(rows)]
    levels = [[0 for x in range(cols)] for y in range(rows)]
    
    curr_max_lg = 1
    curr_max_lvl = 0

    for r in range(rows):
        for c in range(cols):
            skimap, lengths, levels, rows, cols, max_lg, max_lvl = get_lg_lvl(skimap,lengths,levels,rows,cols,r,c)
            if max_lg > curr_max_lg:
                curr_max_lg = max_lg
                curr_max_lvl = max_lvl
            elif max_lg == curr_max_lg:
                if max_lvl > curr_max_lvl:
                    curr_max_lg = max_lg
                    curr_max_lvl = max_lvl

    print curr_max_lg, curr_max_lvl