P1001 （C语言代码）

解题思路:

注意事项:

参考代码:

#include<stdio.h>

#include<math.h>

int Confirm(int n){        //确定是否为质数

         if(n<2)

         return 0;

         for(int i=2;i<=sqrt(n);i++){

         if(n%i==0)

         return 0;

         }

         return 1;

}

int main(){

         int n,k;

         int a[10000];

         scanf("%d %d",&n,&k); 

         while(n<=0 || n>10000 || k<=0 || k>n){        //n,k的范围判断

                 scanf("%d %d",&n,&k); 

         }

         for(int i=0;i<n;i++){                                        //输入序列

                 scanf("%d",&a[i]);

         }

         for(int i=0;i<n;i++){                                        //序列排序

                 for(int j=0;j<i;j++){

                         if(a[i]<a[j]){

                                 int t=a[i];

                                 a[i]=a[j];

                                 a[j]=t;

                         }

                 }

         }

         int m=a[n-k]-a[k-1];                                    //计算m

         if(Confirm(m)==1){

                  printf("YES\n");

         }

         else{

                 printf("NO\n");

         }

         printf("%d",m);

         return 0;

}