编写题解 1268: P1001(python代码）

解题思路:

注意事项:

参考代码:

def isprime(x):
    ls=[1,3,7,9]
    lis=[2,3,5,7]
    if x <1:
        return 0
    elif 1<=x<10:
        if x in lis:
            return 1 
        else:
            return 0
    else:
        if int(str(x)[-1:]) not in ls:
            return 0 
        else:
            s = 0
            for i in range(2,x//2+1):
                if x%i==0:
                    s += 1  
                    break
            if s == 0:
                return 1 
            else:
                return 0
b,s= map(int,input().split())
ls=list(map(int,input().split()))
ls.sort()
sn=ls[s-1]
bn=ls[::-1][s-1]
if isprime(bn-sn):
    print('YES')
else:
    print('NO')
print(bn-sn)