mat_util.cc

   1 #include <assert.h>
   2 #include <NTL/vec_ZZ.h>
   3 #include <NTL/mat_ZZ.h>
   4 #include "mat_util.h"
   5
   6 int lex_cmp(const vec_ZZ& a, const vec_ZZ& b)
   7 {
   8     assert(a.length() == b.length());
   9
  10     for (int j = 0; j < a.length(); ++j)
  11         if (a[j] != b[j])
  12             return a[j] < b[j] ? -1 : 1;
  13     return 0;
  14 }
  15
  16 void lex_order_rows(mat_ZZ& mat)
  17 {
  18     for (int i = 0; i < mat.NumRows(); ++i) {
  19         int m = i;
  20         for (int j = i+1; j < mat.NumRows(); ++j)
  21             if (lex_cmp(mat[j], mat[m]) < 0)
  22                 m = j;
  23         if (m != i) {
  24             vec_ZZ tmp = mat[m];
  25             mat[m] = mat[i];
  26             mat[i] = tmp;
  27         }
  28     }
  29 }
  30
  31 int lex_cmp(const mat_ZZ& a, const mat_ZZ& b)
  32 {
  33     assert(a.NumCols() == b.NumCols());
  34     int alen = a.NumRows();
  35     int blen = b.NumRows();
  36     int len = alen < blen ? alen : blen;
  37
  38     for (int i = 0; i < len; ++i) {
  39         int s = lex_cmp(a[i], b[i]);
  40         if (s)
  41             return s;
  42     }
  43     return alen-blen;
  44 }