15 Beijing Regional Competition--construction--hihocoder 1257 Snake Carper

Note that it is a positive even number. Not including 0

And when there's n=2, you should put it sideways.

#include <cstdio> #include <algorithm>using namespace std;void dfs (int n) {if (n = = 1) {printf ("1 1\n"        );    Return        } else if (n ==2) {printf ("1 1\n");        printf ("1 2 1 3\n");    Return        } else if (n = = 3) {printf ("1 2\n");        printf ("1 1 2 1\n");        printf ("1 3 2 3 2 2\n");    Return        } else if (n% 2 = = 1) {DFS (n-3);        int num = (n-3) * (n-2)/2;        int col = (n-2)/2;        int row = Num/col;        N-2 for (int i = 1; I <= col; i++) printf ("%d%d", I, row+1);        printf ("%d%d", col+1, row+1);        for (int i = 1; I <= col; i++) {printf ("%d%d", col+1, row-i+1);        } puts ("");        N-1 for (int i = 1; I <= (n-1)/2; i++) printf ("%d%d", col+1, I);        for (int i = (n-1)/2; I >= 1; i--) printf ("%d%d", col+2, I);       Puts (""); n for (int i = 1; I <= n/2; i++) printf ("%d%d", COl+2, (n-1)/2+i);       printf ("%d%d", col+2, row+2);       for (int i = 1; I <= n/2; i++) printf ("%d%d", col+2-i, row+2);    Puts ("");       } else {DFS (n-1);       int num = (n-1) *N/2;       int col = N/2;       int row = Num/col;       for (int i = 1; I <= n/2; i++) printf ("%d%d", I, row+1);       for (int i = N/2; I >= 1; i--) printf ("%d%d", I, row+2);    Puts ("");    }}int Main () {int n;        while (~SCANF ("%d", &n)) {int xx, yy;             if (n% 2 = = 1) {xx = (n+1)/2;        yy = N;             } else {xx = N/2;        yy = n+1;    } printf ("%d%d\n", XX, yy);    DFS (n); } return 0;}

　　

15 Beijing Regional Competition--construction--hihocoder 1257 Snake Carper