#include <stdio.h>
        #include <string.h>
        #include <assert.h>

        #define MAXX 48
        void reset(unsigned char *buffer) {
          for (int i = 0; i < MAXX; i++) buffer[i] = i+1;
        }
        void dump(unsigned char *buffer) {
          for (int i = 0; i < MAXX-1; i++) printf("%2d,", buffer[i]);
          printf("%d\n", buffer[MAXX-1]);
        }
        int main() {
          unsigned char buffer[MAXX];
          for (int i = MAXX/4; i < MAXX-MAXX/4; i++) {
            for (int j = MAXX/4; j < MAXX-MAXX/4; j++) {
              for (int k = 1; k < MAXX/4; k++) {
                if (i == j) continue;
                if (i < j && i+k > j) continue;
                if (j < i && j+k > i) continue;
                printf("[%d,%d,%d] ", i, j, k);
                reset(buffer);
                memcpy(buffer+i, buffer+j, k);
                dump(buffer);
                assert(memcmp(buffer+i, buffer+j, k) == 0);
                buffer[i + k/2]++;
                if (buffer[i + k/2] != 0) {
                  assert(memcmp(buffer+i, buffer+j, k) > 0);
                } else {
                  assert(memcmp(buffer+i, buffer+j, k) < 0);
                }
                buffer[i + k/2]--;
                buffer[j + k/2]++;
                if (buffer[j + k/2] != 0) {
                  assert(memcmp(buffer+i, buffer+j, k) < 0);
                } else {
                  assert(memcmp(buffer+i, buffer+j, k) > 0);
                }
              }
            }
          }
          return 0;
        }