Submission #647160

#	Time	Username	Problem	Language	Result	Execution time	Memory
647160		beaconmc	The Kingdom of JOIOI (JOI17_joioi)	Pypy 3	60 / 100	1389 ms	262144 KiB

joioi

from copy import *
n,m = map(int, input().split())
 
grid = [list(map(int, input().split()))for i in range(n)]
 
mx = -1
ll = 1000000000
for i in range(n):
    for j in range(m):
        mx = max(mx, grid[i][j])
        ll = min(ll, grid[i][j])

 
 
minmaxl = [[(float("inf"), -1)for i in range(m)]for i in range(n)]
minmaxr = [[(float("inf"), -1)for i in range(m)]for i in range(n)]
def setup():
    for i in range(n-1,-1,-1):
        minmaxl[i][0] = [grid[i][0], grid[i][0]]
        for j in range(1,m):
            minmaxl[i][j] = (min(minmaxl[i][j-1][0], grid[i][j]),max(minmaxl[i][j-1][1], grid[i][j]))
        if i != n-1:
            for j in range(m):
                minmaxl[i][j] = (min(minmaxl[i][j][0], minmaxl[i+1][j][0]),max(minmaxl[i][j][1], minmaxl[i+1][j][1]))
 
    for i in range(n-1,-1,-1):
        minmaxr[i][m-1] = (grid[i][m-1], grid[i][m-1])
        for j in range(m-2,-1,-1):
            minmaxr[i][j] = (min(minmaxr[i][j+1][0], grid[i][j]),max(minmaxr[i][j+1][1], grid[i][j]))

        if i != n-1:
            for j in range(m-1,-1,-1):
                minmaxr[i][j] = (min(minmaxr[i][j][0], minmaxr[i+1][j][0]),max(minmaxr[i][j][1], minmaxr[i+1][j][1])) 
def check(a):
 
    mini = float("inf")
    maxi = -1
    for i in range(n):
        for j in range(m):
            if mx - minmaxl[i][j][0] > a:
                mini = min(mini, grid[i][j])
                maxi = max(maxi, grid[i][j])
    if maxi - mini <= a:
        return True
    
    mini = float("inf")
    maxi = -1
    for i in range(n):
        for j in range(m):
            if minmaxl[i][j][1]-ll > a:
                mini = min(mini, grid[i][j])
                maxi = max(maxi, grid[i][j])
    if maxi - mini <= a:
        return True
    
 
    mini = float("inf")
    maxi = -1
    for i in range(n):
        for j in range(m):
            if mx - minmaxr[i][j][0] > a:
                mini = min(mini, grid[i][j])
                maxi = max(maxi, grid[i][j])
    if maxi - mini <= a:
        return True


    mini = float("inf")
    maxi = -1
    for i in range(n):
        for j in range(m):
            if minmaxr[i][j][1]-ll > a:
                mini = min(mini, grid[i][j])
                maxi = max(maxi, grid[i][j])
    if maxi - mini <= a:
        return True
    return False


 
setup()
lo = 0
hi = 10000000000
while (lo<hi):
    mid = (lo+hi)//2
    if check(mid):
        hi = mid
    else:
        lo = mid+1
ans = lo
print(ans)
 
    

• Subtask 1: 15 / 15
• Subtask 2: 45 / 45
• Subtask 3: 0 / 40