6 int readPaulicoeffs(int* alpha, int* beta, int* gamma, int* delta, int numqubits);
7 complex double Gausssum1d(int quadraticcoeff, int linearcoeff);
8 complex double Kroneck(int arg);
10 // order of matrix elements is [row][column]!!!
18 int N; // number of qubits
21 printf("Error: N must be a multiple of 6!\n");
25 int alpha[N], beta[N], gamma[N], delta[N];
27 double complex summand, sum;
29 while(readPaulicoeffs(alpha, beta, gamma, delta, N)) {
31 /* for(i=0; i<N; i++) */
32 /* printf("%d %d %d %d\n", alpha[i], beta[i], gamma[i], delta[i]); */
38 //for(x=0;x<=(y*(gamma[i]+gamma[i+1])+(y+1)*(gamma[i]+delta[i+1]))%2; x++) {
39 for(x=y*(beta[i]+alpha[i+1]+beta[i+1])%2;x<=(y*(beta[i]+alpha[i+1]+beta[i+1])+y*(gamma[i]+gamma[i+1])+(y+1)*(gamma[i]+delta[i+1]))%2; x++) {
40 for(yp=((gamma[i+3]+delta[i+4])*x)%2; yp<=(1+(gamma[i+3]+gamma[i+4])*x)%2; yp++) {
41 //strange that I don't need the following modification to x
42 //****for(yp=((gamma[i+3]+delta[i+4])*x*(1+alpha[i]+beta[i]))%2; yp<=(1+(gamma[i+3]+gamma[i+4])*x*(1+alpha[i]+beta[i]))%2; yp++) {
43 for(xp=yp*(beta[i+3]+alpha[i+4]+beta[i+4])%2;xp<=(yp*(beta[i+3]+alpha[i+4]+beta[i+4])+yp*(gamma[i+3]+gamma[i+4])+(yp+1)*(gamma[i+3]+delta[i+4]))%2; xp++) {
44 //for(xp=0;xp<=(yp*(gamma[i+3]+gamma[i+4])+(yp+1)*(gamma[i+3]+delta[i+4]))%2; xp++) {
45 summand += 2.0*(0.125*pow(2.0,(1-y*pow(gamma[i]-gamma[i+1],2)-pow(y-1,2)*pow(gamma[i]-delta[i+1],2))*(1-yp*pow(gamma[i+3]-gamma[i+4],2)-pow(yp-1,2)*pow(gamma[i+3]-delta[i+4],2)))*cexp(M_PI*I/2.0*((delta[i+1]-gamma[i])*pow(y+1,2)+2.0*(beta[i]+beta[i+1]+gamma[i]+delta[i+1])*x*pow(y+1,2)+2.0*(delta[i]+delta[i+1]+beta[i]+beta[i+1])*x*y+(2.0*beta[i]+3.0*delta[i]+delta[i+1])*y))*Gausssum1d(0.0,beta[i+2])*Kroneck(gamma[i]+delta[i]-gamma[i+1]-delta[i+1])*Kroneck(gamma[i+2]+delta[i+2])
46 + 0.125*pow(2.0,(1-y*pow(gamma[i]-gamma[i+1],2)-pow(y-1,2)*pow(gamma[i]-delta[i+1],2))*(1-yp*pow(gamma[i+3]-gamma[i+4],2)-pow(yp-1,2)*pow(gamma[i+3]-delta[i+4],2)))*cexp(M_PI*I/2.0*((delta[i+1]-gamma[i])*pow(y+1,2)+2.0*(beta[i]+beta[i+1]+gamma[i]+delta[i+1])*x*pow(y+1,2)+2.0*(delta[i]+delta[i+1]+beta[i]+beta[i+1])*x*y+(2.0*beta[i]+3.0*delta[i]+delta[i+1])*y))*csqrt(-I)*Gausssum1d(gamma[i+2]+delta[i+2],0)*Kroneck(gamma[i]+delta[i]-gamma[i+1]-delta[i+1])*Kroneck(alpha[i+2]+beta[i+2]))
47 *(0.125*cexp(M_PI*I/2.0*((delta[i+4]-gamma[i+3])*pow(yp+1,2)+2.0*(beta[i+3]+beta[i+4]+gamma[i+3]+delta[i+4])*xp*pow(yp+1,2)+2.0*(delta[i+3]+delta[i+4]+beta[i+3]+beta[i+4])*xp*yp+(2.0*beta[i+3]+3.0*delta[i+3]+delta[i+4])*yp))*Gausssum1d(0.0,beta[i+5])*Kroneck(gamma[i+3]+delta[i+3]-gamma[i+4]-delta[i+4])*Kroneck(gamma[i+5]+delta[i+5])
48 + 0.125*cexp(M_PI*I/2.0*((delta[i+4]-gamma[i+3])*pow(yp+1,2)+2.0*(beta[i+3]+beta[i+4]+gamma[i+3]+delta[i+4])*xp*pow(yp+1,2)+2.0*(delta[i+3]+delta[i+4]+beta[i+3]+beta[i+4])*xp*yp+(2.0*beta[i+3]+3.0*delta[i+3]+delta[i+4])*yp))*csqrt(-I)*Gausssum1d(gamma[i+5]+delta[i+5],0)*Kroneck(gamma[i+3]+delta[i+3]-gamma[i+4]-delta[i+4])*Kroneck(alpha[i+5]+beta[i+5]));
51 for(yp=0; yp<=(1+alpha[i+5])%2; yp++) {
52 for(xp=0;xp<=(1+beta[i+5])%2; xp++) {
53 summand += (0.125*pow(2.0,1-y*pow(gamma[i]-gamma[i+1],2)-pow(y-1,2)*pow(gamma[i]-delta[i+1],2))*cexp(M_PI*I/2.0*((delta[i+1]-gamma[i])*pow(y+1,2)+2.0*(beta[i]+beta[i+1]+gamma[i]+delta[i+1])*x*pow(y+1,2)+2.0*(delta[i]+delta[i+1]+beta[i]+beta[i+1])*x*y+(2.0*beta[i]+3.0*delta[i]+delta[i+1])*y))*Gausssum1d(0.0,beta[i+2])*Kroneck(gamma[i]+delta[i]-gamma[i+1]-delta[i+1])*Kroneck(gamma[i+2]+delta[i+2])
54 + 0.125*pow(2.0,1-y*pow(gamma[i]-gamma[i+1],2)-pow(y-1,2)*pow(gamma[i]-delta[i+1],2))*cexp(M_PI*I/2.0*((delta[i+1]-gamma[i])*pow(y+1,2)+2.0*(beta[i]+beta[i+1]+gamma[i]+delta[i+1])*x*pow(y+1,2)+2.0*(delta[i]+delta[i+1]+beta[i]+beta[i+1])*x*y+(2.0*beta[i]+3.0*delta[i]+delta[i+1])*y))*csqrt(-I)*Gausssum1d(gamma[i+2]+delta[i+2],0)*Kroneck(gamma[i]+delta[i]-gamma[i+1]-delta[i+1])*Kroneck(alpha[i+2]+beta[i+2]))
55 *(0.125*2.0*csqrt(-I)*cexp(M_PI*I/2.0*(2.0*beta[i+5]*yp+pow(xp+1,2)*(delta[i+3]+gamma[i+4]+2.0*beta[i+4])+xp*(delta[i+3]+delta[i+4])))*Gausssum1d(1,beta[i+3]+beta[i+4]+delta[i+3]+(xp+1)*gamma[i+4]+xp*delta[i+4])*Kroneck(gamma[i+3]+delta[i+3]-gamma[i+4]-delta[i+4]+1)*Kroneck(gamma[i+5]+delta[i+5]));
58 //for(yp=x; yp<=1; yp++) {
59 for(yp=x*(1+alpha[i]+beta[i])%2; yp<=1; yp++) {
60 //for(xp=(yp*(delta[i+3]+delta[i+4])+x)%2;xp<=(1+yp*(gamma[i+3]+gamma[i+4])+x)%2; xp++) {
61 for(xp=(yp*(delta[i+3]+delta[i+4])+x*(1+alpha[i]+beta[i]))%2;xp<=(1+yp*(gamma[i+3]+gamma[i+4])+x*(1+alpha[i]+beta[i]))%2; xp++) {
62 summand += 2.0*(0.125*pow(2.0,(1-y*pow(gamma[i]-gamma[i+1],2)-pow(y-1,2)*pow(gamma[i]-delta[i+1],2))*(pow(yp-1,2)*(pow(xp,2)*(gamma[i+3]+delta[i+4])+pow(xp-1,2)*(gamma[i+4]+delta[i+3]))))*cexp(M_PI*I/2.0*((delta[i+1]-gamma[i])*pow(y+1,2)+2.0*(beta[i]+beta[i+1]+gamma[i]+delta[i+1])*x*pow(y+1,2)+2.0*(delta[i]+delta[i+1]+beta[i]+beta[i+1])*x*y+(2.0*beta[i]+3.0*delta[i]+delta[i+1])*y))*Gausssum1d(0.0,beta[i+2])*Kroneck(gamma[i]+delta[i]-gamma[i+1]-delta[i+1])*Kroneck(gamma[i+2]+delta[i+2])
63 + 0.125*pow(2.0,(1-y*pow(gamma[i]-gamma[i+1],2)-pow(y-1,2)*pow(gamma[i]-delta[i+1],2))*(pow(yp-1,2)*(pow(xp,2)*(gamma[i+3]+delta[i+4])+pow(xp-1,2)*(gamma[i+4]+delta[i+3]))))*cexp(M_PI*I/2.0*((delta[i+1]-gamma[i])*pow(y+1,2)+2.0*(beta[i]+beta[i+1]+gamma[i]+delta[i+1])*x*pow(y+1,2)+2.0*(delta[i]+delta[i+1]+beta[i]+beta[i+1])*x*y+(2.0*beta[i]+3.0*delta[i]+delta[i+1])*y))*csqrt(-I)*Gausssum1d(gamma[i+2]+delta[i+2],0)*Kroneck(gamma[i]+delta[i]-gamma[i+1]-delta[i+1])*Kroneck(alpha[i+2]+beta[i+2]))
64 *(0.125*(-I)*cexp(M_PI*I/2.0*(yp*(delta[i+3]+delta[i+4])+pow(yp+1,2)*(delta[i+3]+gamma[i+4]+2*beta[i+4])+pow(xp,2)+2*(beta[i+3]+beta[i+4]+delta[i+3]+gamma[i+4]*(yp+1)+delta[i+4]*yp)*xp))*Gausssum1d(0,xp+beta[i+3]+beta[i+4]+delta[i+3]+gamma[i+4]*(yp+1)+delta[i+4]*yp+gamma[i+5]+delta[i+5])*Kroneck(gamma[i+3]+delta[i+3]-gamma[i+4]-delta[i+4]+1)*Kroneck(alpha[i+5]+beta[i+5]));
70 for(y=0; y<=(1+alpha[i+2])%2; y++) {
71 for(x=0; x<=(1+beta[i+2])%2; x++) {
72 for(yp=0; yp<=1; yp++) {
73 for(xp=yp*(beta[i+3]+alpha[i+4]+beta[i+4])%2;xp<=(yp*(beta[i+3]+alpha[i+4]+beta[i+4])+yp*(gamma[i+3]+gamma[i+4])+(yp+1)*(gamma[i+3]+delta[i+4]))%2; xp++) {
74 //for(xp=0;xp<=(yp*(gamma[i+3]+gamma[i+4])+(yp+1)*(gamma[i+3]+delta[i+4]))%2; xp++) {
75 summand += (0.125*2.0*csqrt(-I)*cexp(M_PI*I/2.0*(2.0*beta[i+2]*y+pow(x+1,2)*(delta[i]+gamma[i+1]+2.0*beta[i+1])+x*(delta[i]+delta[i+1])))*Gausssum1d(1,beta[i]+beta[i+1]+delta[i]+(x+1)*gamma[i+1]+x*delta[i+1])*Kroneck(gamma[i]+delta[i]-gamma[i+1]-delta[i+1]+1)*Kroneck(gamma[i+2]+delta[i+2]))
76 *(0.125*pow(2.0,1-yp*pow(gamma[i+3]-gamma[i+4],2)-pow(yp-1,2)*pow(gamma[i+3]-delta[i+4],2))*cexp(M_PI*I/2.0*((delta[i+4]-gamma[i+3])*pow(yp+1,2)+2.0*(beta[i+3]+beta[i+4]+gamma[i+3]+delta[i+4])*xp*pow(yp+1,2)+2.0*(delta[i+3]+delta[i+4]+beta[i+3]+beta[i+4])*xp*yp+(2.0*beta[i+3]+3.0*delta[i+3]+delta[i+4])*yp))*Gausssum1d(0.0,beta[i+5])*Kroneck(gamma[i+3]+delta[i+3]-gamma[i+4]-delta[i+4])*Kroneck(gamma[i+5]+delta[i+5])
77 + 0.125*pow(2.0,1-yp*pow(gamma[i+3]-gamma[i+4],2)-pow(yp-1,2)*pow(gamma[i+3]-delta[i+4],2))*cexp(M_PI*I/2.0*((delta[i+4]-gamma[i+3])*pow(yp+1,2)+2.0*(beta[i+3]+beta[i+4]+gamma[i+3]+delta[i+4])*xp*pow(yp+1,2)+2.0*(delta[i+3]+delta[i+4]+beta[i+3]+beta[i+4])*xp*yp+(2.0*beta[i+3]+3.0*delta[i+3]+delta[i+4])*yp))*csqrt(-I)*Gausssum1d(gamma[i+5]+delta[i+5],0)*Kroneck(gamma[i+3]+delta[i+3]-gamma[i+4]-delta[i+4])*Kroneck(alpha[i+5]+beta[i+5]));
80 for(yp=0; yp<=(1+alpha[i+5])%2; yp++) {
81 for(xp=0;xp<=(1+beta[i+5])%2; xp++) {
82 summand += (0.125*2.0*csqrt(-I)*cexp(M_PI*I/2.0*(2.0*beta[i+2]*y+pow(x+1,2)*(delta[i]+gamma[i+1]+2.0*beta[i+1])+x*(delta[i]+delta[i+1])))*Gausssum1d(1,beta[i]+beta[i+1]+delta[i]+(x+1)*gamma[i+1]+x*delta[i+1])*Kroneck(gamma[i]+delta[i]-gamma[i+1]-delta[i+1]+1)*Kroneck(gamma[i+2]+delta[i+2]))
83 *(0.125*2.0*csqrt(-I)*cexp(M_PI*I/2.0*(2.0*beta[i+5]*yp+pow(xp+1,2)*(delta[i+3]+gamma[i+4]+2.0*beta[i+4])+xp*(delta[i+3]+delta[i+4])))*Gausssum1d(1,beta[i+3]+beta[i+4]+delta[i+3]+(xp+1)*gamma[i+4]+xp*delta[i+4])*Kroneck(gamma[i+3]+delta[i+3]-gamma[i+4]-delta[i+4]+1)*Kroneck(gamma[i+5]+delta[i+5]));
86 for(yp=0; yp<=1; yp++) {
87 for(xp=(yp*(delta[i+3]+delta[i+4]))%2;xp<=(1+yp*(gamma[i+3]+gamma[i+4]))%2; xp++) {
88 summand += (0.125*2.0*csqrt(-I)*cexp(M_PI*I/2.0*(2.0*beta[i+2]*y+pow(x+1,2)*(delta[i]+gamma[i+1]+2.0*beta[i+1])+x*(delta[i]+delta[i+1])))*Gausssum1d(1,beta[i]+beta[i+1]+delta[i]+(x+1)*gamma[i+1]+x*delta[i+1])*Kroneck(gamma[i]+delta[i]-gamma[i+1]-delta[i+1]+1)*Kroneck(gamma[i+2]+delta[i+2]))
89 *(0.125*(-I)*pow(2.0,(pow(yp-1,2)*(pow(xp,2)*(gamma[i+3]+delta[i+4])+pow(xp-1,2)*(gamma[i+4]+delta[i+3]))))*cexp(M_PI*I/2.0*(yp*(delta[i+3]+delta[i+4])+pow(yp+1,2)*(delta[i+3]+gamma[i+4]+2*beta[i+4])+pow(xp,2)+2*(beta[i+3]+beta[i+4]+delta[i+3]+gamma[i+4]*(yp+1)+delta[i+4]*yp)*xp))*Gausssum1d(0,xp+beta[i+3]+beta[i+4]+delta[i+3]+gamma[i+4]*(yp+1)+delta[i+4]*yp+gamma[i+5]+delta[i+5])*Kroneck(gamma[i+3]+delta[i+3]-gamma[i+4]-delta[i+4]+1)*Kroneck(alpha[i+5]+beta[i+5]));
96 for(x=(y*(delta[i]+delta[i+1]))%2; x<=(1+y*(gamma[i]+gamma[i+1]))%2; x++) {
97 for(yp=((gamma[i+3]+delta[i+4])*y)%2; yp<=(1+(gamma[i+3]+gamma[i+4])*y)%2; yp++) {
98 for(xp=yp*(beta[i+3]+alpha[i+4]+beta[i+4])%2;xp<=(yp*(beta[i+3]+alpha[i+4]+beta[i+4])+yp*(gamma[i+3]+gamma[i+4])+(yp+1)*(gamma[i+3]+delta[i+4]))%2; xp++) {
99 //for(xp=0;xp<=(yp*(gamma[i+3]+gamma[i+4])+(yp+1)*(gamma[i+3]+delta[i+4]))%2; xp++) {
100 summand += 2.0*(0.125*pow(2.0,(pow(y-1,2)*(pow(x,2)*(gamma[i]+delta[i+1])+pow(x-1,2)*(gamma[i+1]+delta[i])))*(1-yp*pow(gamma[i+3]-gamma[i+4],2)-pow(yp-1,2)*pow(gamma[i+3]-delta[i+4],2)))*(-I)*cexp(M_PI*I/2.0*(y*(delta[i]+delta[i+1])+pow(y+1,2)*(delta[i]+gamma[i+1]+2*beta[i+1])+pow(x,2)+2*(beta[i]+beta[i+1]+delta[i]+gamma[i+1]*(y+1)+delta[i+1]*y)*x))*Gausssum1d(0,x+beta[i]+beta[i+1]+delta[i]+gamma[i+1]*(y+1)+delta[i+1]*y+gamma[i+2]+delta[i+2])*Kroneck(gamma[i]+delta[i]-gamma[i+1]-delta[i+1]+1)*Kroneck(alpha[i+2]+beta[i+2]))
101 *(0.125*cexp(M_PI*I/2.0*((delta[i+4]-gamma[i+3])*pow(yp+1,2)+2.0*(beta[i+3]+beta[i+4]+gamma[i+3]+delta[i+4])*xp*pow(yp+1,2)+2.0*(delta[i+3]+delta[i+4]+beta[i+3]+beta[i+4])*xp*yp+(2.0*beta[i+3]+3.0*delta[i+3]+delta[i+4])*yp))*Gausssum1d(0.0,beta[i+5])*Kroneck(gamma[i+3]+delta[i+3]-gamma[i+4]-delta[i+4])*Kroneck(gamma[i+5]+delta[i+5])
102 + 0.125*cexp(M_PI*I/2.0*((delta[i+4]-gamma[i+3])*pow(yp+1,2)+2.0*(beta[i+3]+beta[i+4]+gamma[i+3]+delta[i+4])*xp*pow(yp+1,2)+2.0*(delta[i+3]+delta[i+4]+beta[i+3]+beta[i+4])*xp*yp+(2.0*beta[i+3]+3.0*delta[i+3]+delta[i+4])*yp))*csqrt(-I)*Gausssum1d(gamma[i+5]+delta[i+5],0)*Kroneck(gamma[i+3]+delta[i+3]-gamma[i+4]-delta[i+4])*Kroneck(alpha[i+5]+beta[i+5]));
105 for(yp=0; yp<=(1+alpha[i+5])%2; yp++) {
106 for(xp=0;xp<=(1+beta[i+5])%2; xp++) {
107 summand += (0.125*pow(2.0,pow(y-1,2)*(pow(x,2)*(gamma[i]+delta[i+1])+pow(x-1,2)*(gamma[i+1]+delta[i])))*(-I)*cexp(M_PI*I/2.0*(y*(delta[i]+delta[i+1])+pow(y+1,2)*(delta[i]+gamma[i+1]+2*beta[i+1])+pow(x,2)+2*(beta[i]+beta[i+1]+delta[i]+gamma[i+1]*(y+1)+delta[i+1]*y)*x))*Gausssum1d(0,x+beta[i]+beta[i+1]+delta[i]+gamma[i+1]*(y+1)+delta[i+1]*y+gamma[i+2]+delta[i+2])*Kroneck(gamma[i]+delta[i]-gamma[i+1]-delta[i+1]+1)*Kroneck(alpha[i+2]+beta[i+2]))
108 *(0.125*2.0*csqrt(-I)*cexp(M_PI*I/2.0*(2.0*beta[i+5]*yp+pow(xp+1,2)*(delta[i+3]+gamma[i+4]+2.0*beta[i+4])+xp*(delta[i+3]+delta[i+4])))*Gausssum1d(1,beta[i+3]+beta[i+4]+delta[i+3]+(xp+1)*gamma[i+4]+xp*delta[i+4])*Kroneck(gamma[i+3]+delta[i+3]-gamma[i+4]-delta[i+4]+1)*Kroneck(gamma[i+5]+delta[i+5]));
111 for(yp=y; yp<=1; yp++) {
112 for(xp=(yp*(delta[i+3]+delta[i+4])+y)%2;xp<=(1+yp*(gamma[i+3]+gamma[i+4])+y)%2; xp++) {
113 summand += 2.0*(0.125*pow(2.0,(pow(y-1,2)*(pow(x,2)*(gamma[i]+delta[i+1])+pow(x-1,2)*(gamma[i+1]+delta[i])))*(pow(yp-1,2)*(pow(xp,2)*(gamma[i+3]+delta[i+4])+pow(xp-1,2)*(gamma[i+4]+delta[i+3]))))*(-I)*cexp(M_PI*I/2.0*(y*(delta[i]+delta[i+1])+pow(y+1,2)*(delta[i]+gamma[i+1]+2*beta[i+1])+pow(x,2)+2*(beta[i]+beta[i+1]+delta[i]+gamma[i+1]*(y+1)+delta[i+1]*y)*x))*Gausssum1d(0,x+beta[i]+beta[i+1]+delta[i]+gamma[i+1]*(y+1)+delta[i+1]*y+gamma[i+2]+delta[i+2])*Kroneck(gamma[i]+delta[i]-gamma[i+1]-delta[i+1]+1)*Kroneck(alpha[i+2]+beta[i+2]))
114 *(0.125*(-I)*cexp(M_PI*I/2.0*(yp*(delta[i+3]+delta[i+4])+pow(yp+1,2)*(delta[i+3]+gamma[i+4]+2*beta[i+4])+pow(xp,2)+2*(beta[i+3]+beta[i+4]+delta[i+3]+gamma[i+4]*(yp+1)+delta[i+4]*yp)*xp))*Gausssum1d(0,xp+beta[i+3]+beta[i+4]+delta[i+3]+gamma[i+4]*(yp+1)+delta[i+4]*yp+gamma[i+5]+delta[i+5])*Kroneck(gamma[i+3]+delta[i+3]-gamma[i+4]-delta[i+4]+1)*Kroneck(alpha[i+5]+beta[i+5]));
122 //printf("%lf+%lfI\n", creal(sum), cimag(sum));
123 printf("%lf\n", cabs(creal(sum)));
131 complex double Kroneck(int arg)
133 arg = (arg+1)%2; // output 1 if argument is 0 mod 2 and 0 otherwise
134 return ((complex double)arg);
137 complex double Gausssum1d(int quadraticcoeff, int linearcoeff)
139 /*****************************************
140 /* NOTE! we assume coeffs are either 0 or 1
141 /* (So you cannot pass off a linear coeff as a quadratic coeff by multiplying it by a factor of 2 (and considering it as mod 4)!)
142 *****************************************/
147 if(quadraticcoeff == 0)
160 int readPaulicoeffs(int *alpha, int *beta, int *gamma, int *delta, int numqubits)
165 if(scanf("%d %d %d %d", &alpha[0], &beta[0], &gamma[0], &delta[0]) != EOF) {
166 for(i=1; i<numqubits; i++) {
167 scanf("%d %d %d %d", &alpha[i], &beta[i], &gamma[i], &delta[i]);