added core code, README, and testing scripts

[strong_simulation_stabilizer_rank.git] / randominputcommutingHermitianPauli.c

diff --git a/randominputcommutingHermitianPauli.c b/randominputcommutingHermitianPauli.c
new file mode 100644 (file)
index 0000000..348a9c1
--- /dev/null
+++ b/randominputcommutingHermitianPauli.c
@@ -0,0 +1,58 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <string.h>
+
+// order of matrix elements is [row][column]!!!
+
+/*********************************************************/
+/* Generates random Hermitian Paulis that are commuting! */
+/*********************************************************/
+int main( int argc, char *argv[])
+{
+
+  if(argc != 3) {
+    printf("randominputPauli arguments: \"number of qubits\" \"number of T gates\"\n");
+    exit(0);
+  }
+  
+  int N = atoi(argv[1]);              // number of qubits
+  int T = atoi(argv[2]);              // number of T gate magic states (set to the first 'K' of the 'N' qubits -- the rest are set to the '0' computational basis state)
+
+  printf("%d\n", N);
+  printf("%d\n", T);
+
+  int Pauli[N][N];
+  srand((unsigned)time(NULL));
+
+
+  int i, j, k;
+
+  int sign = 1;
+  
+  for(i=0; i<N; i++) {
+    
+    for(j=0; j<N; j++) {
+      Pauli[i][j] = rand()%3; // don't generate Y's (which is represented by '3'; I=0, Z=1, X=2, Y=3)
+    }
+    // see if the new Paulis commute with all the previous ones
+    for(j=0; j<i; j++) {
+      sign = 1;
+      for(k=0; k<N; k++) {
+       if(Pauli[j][k] != Pauli[i][k] && Pauli[j][k] != 0 && Pauli[i][k] != 0) // if the Paulis are different and neither is equal to the identity then they anticommute
+         sign *= -1;
+      }
+      if(sign == -1) {
+       i--; // try generating the ith set of Paulis again to get a commuting one
+       break; // break out of the loop over j
+      }
+    }
+    if(sign == 1) { // found a commuting set!
+      printf("%d\n", (rand()%2)*2); // omega must be 0 or 2 (since it is the power of i: i^omega)
+      for(j=0; j<N; j++) {
+       printf("%d %d %d %d\n", Pauli[i][j]==0, Pauli[i][j]==1, Pauli[i][j]==2, Pauli[i][j]==3);
+      }
+    }
+  }
+
+}