int main(int argc,char *argv[]) {
int Pa(int low,int high,int length,char *str);
int iseven(int n);
int isodd(int n);
char str[]="aabaa";
int len;
len = strlen(str);
if(Pa(0,len-1,len,str)) {
printf("this string is a Pa string\n");
}
printf("3:%d 4:%d\n",iseven(0),iseven(4));
}
int PE2main(pe_data_t *pedata)
{
unsigned int next = 0;
unsigned int current = 1, last = 0, totaleven = 0;
printf("Running Project Euler Problem 2\n");
while (1)
{
next = current + last;
last = current;
current = next;
if (next > 4000000)
break;
if(iseven(next))
totaleven = totaleven + next;
/*printf ("Currently at: %i\n", current);*/
}
if (pedata->verbosity > 0) printf("Total: %i\n", totaleven);
sprintf(pedata->result,"%i",totaleven);
return 0;
}
int func(int b,int n) {
if (n == 0) {
return 1;
}
else {
return iseven( n ) ? func ( square(b) , halve( n ) ) : b * func( b , n-1 ) ;
}
}
char *num2bin(unsigned long long num, char *buf, size_t n)
{
char s;
buf[n-1] = 0;
while (--n) {
s = iseven(num) ? '0' : '1';
buf[n-1] = s;
if (!(num /= 2))
break;
}
return &buf[n-1];
}
void half_even(int a[], int num){
int left = 0;
int right = num - 1;
int tmp;
if((a == NULL)||(num == 0)){
printf("empty array\n");
exit(1);
}
while(left < right){
if(iseven(a[left])&&(!iseven(a[right]))){
tmp = a[left];
a[left] = a[right];
a[right] = tmp;
}
if(!iseven(a[left]))
left++;
if(iseven(a[right]))
right--;
}
}
int isodd(int n) {
return !(iseven(n));
}
// extended binary gcd
//
// For a anv b it solves, v = gcd(a,b) and finds x and y s.t.
// ax + by = v
//
// Handbook of Applied Cryptography, Menezes et al, 1997, pg 608.
void
mpextendedgcd(mpint *a, mpint *b, mpint *v, mpint *x, mpint *y)
{
mpint *u, *A, *B, *C, *D;
int g;
if(a->top == 0){
mpassign(b, v);
mpassign(mpone, y);
mpassign(mpzero, x);
return;
}
if(b->top == 0){
mpassign(a, v);
mpassign(mpone, x);
mpassign(mpzero, y);
return;
}
g = 0;
a = mpcopy(a);
b = mpcopy(b);
while(iseven(a) && iseven(b)){
mpright(a, 1, a);
mpright(b, 1, b);
g++;
}
u = mpcopy(a);
mpassign(b, v);
A = mpcopy(mpone);
B = mpcopy(mpzero);
C = mpcopy(mpzero);
D = mpcopy(mpone);
for(;;) {
// print("%B %B %B %B %B %B\n", u, v, A, B, C, D);
while(iseven(u)){
mpright(u, 1, u);
if(!iseven(A) || !iseven(B)) {
mpadd(A, b, A);
mpsub(B, a, B);
}
mpright(A, 1, A);
mpright(B, 1, B);
}
// print("%B %B %B %B %B %B\n", u, v, A, B, C, D);
while(iseven(v)){
mpright(v, 1, v);
if(!iseven(C) || !iseven(D)) {
mpadd(C, b, C);
mpsub(D, a, D);
}
mpright(C, 1, C);
mpright(D, 1, D);
}
// print("%B %B %B %B %B %B\n", u, v, A, B, C, D);
if(mpcmp(u, v) >= 0){
mpsub(u, v, u);
mpsub(A, C, A);
mpsub(B, D, B);
} else {
mpsub(v, u, v);
mpsub(C, A, C);
mpsub(D, B, D);
}
if(u->top == 0)
break;
}
mpassign(C, x);
mpassign(D, y);
mpleft(v, g, v);
mpfree(A);
mpfree(B);
mpfree(C);
mpfree(D);
mpfree(u);
mpfree(a);
mpfree(b);
}
