Basic exercises of test questions letter graphics ※

Error model ：

n,m = map(int,input().split())

c = ['A']*m

for i in range(n):
    c[i] = 'A'
    for j in range(i+1,m):
        c[j]=chr(ord(c[j-1])+1)
    if i>=1:
        for k in range(i-1,-1,-1):
            c[k]=chr(ord(c[k+1])+1)
    #print(c,end='')
    for l in range(m):
        print(c[l],end='')
    print()

Cause of error ： Found per line A After the position of , Start generating letters backwards , Then forward to produce letters .

Take a chestnut ,hack data ：26 2

When the number of rows is greater than the number of columns ,A Will disappear , Then I can't find A The array is out of bounds （ stay k Where? ）.

Correct solution , Only describe the relationship （  abs(i-j)  ）, Don't map to position .

n,m = map(int,input().split())

for i in range(n):
    for j in range(m):
        print( chr(ord('A')+abs(i-j)),end='' )
    print()
    

come from ：

Blue Bridge Cup - Based on practice - Alphabetic figure （Python）AC Codes and notes _Harry______ The blog of -CSDN Blog