1 #include <cstdio> 2 #include <cstring> 3 #include <algorithm> 4 using namespace std; 5  6 int a[100010]; 7 int main() 8 { 9     int n,k;10     scanf("%d%d",&n,&k);11     for(int i=1; i<=2*n; i++)12     {13         a[i]=i;14     }15     for(int i=1; i<=k; i++)16     {17         swap(a[2*i-1],a[2*i]);18     }19     for(int i=1; i<=2*n; i++)20     {21         if(i==1) printf("%d",a[i]);22         else printf(" %d",a[i]);23     }24     printf("\n");25     return 0;26 }

 1 #include <cstdio> 2 #include <cstring> 3 #include <algorithm> 4 using namespace std; 5  6 int n,k; 7  8 int main() 9 {10     while(scanf("%d%d",&n,&k)!=EOF)11     {12        printf("%d",k+1);13        for(int i=1; i<=2*n; i++)14        {15            if(i!=k+1) printf(" %d",i);16        }17        printf("\n");18     }19     return 0;20 }