def search_n(s, c, n): |
size = 0 |
for i, x in enumerate (s): |
if x = = c: |
size + = 1 |
if size = = n: |
return i |
return - 1 |
print (search_n( "fdasadfadf" , "a" , 3 )) # 结果为7,正确 |
print (search_n( "fdasadfadf" , "a" , 30 )) # 结果为-1,正确 |