Пример #1
0
// Finds g = gcd(a,b) and x, y such that ax+by=g. Bounds: |x|<=b+1, |y|<=a+1.
void gcdext(LL &g, LL &x, LL &y, LL a, LL b)
{ if (b == 0) { g = a; x = 1; y = 0; } else
{ gcdext(g, y, x, b, a % b); y = y - (a / b) * x; } }
Пример #2
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LL modinv(LL a, LL N)
{
	LL x,y,g; gcdext(g,x,y, a,N );
	assert(g==1); return (x+N)%N;
}
Пример #3
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// Finds g = gcd(a,b) and x, y such that ax+by=g. Bounds: |x|<=b+1, |y|<=a+1.
void gcdext(int &g, int &x, int &y, int a, int b)
{ if (b == 0) { g = a; x = 1; y = 0; }
else { gcdext(g, y, x, b, a % b); y = y - (a / b) * x; } }