PY04-8. Arifmetik progressiya

Arifmetik progressiyada har keyingi had oldingisidan bir xil son d ga farq qiladi: a, a + d, a + 2d, ….

Birinchi had a, ayirma d va son n berilgan. Progressiyaning n-hadini va dastlabki n ta hadining yig‘indisini toping. Sikl ishlatmang — n milliardgacha.

Kirish ma’lumotlari

Bitta qatorda uchta butun son: a, d, n.

Chiqish ma’lumotlari

Bitta qatorda ikki son: n-had va dastlabki n ta had yig‘indisi.

Cheklovlar

−10⁹ ≤ a, d ≤ 10⁹, 1 ≤ n ≤ 10⁹

2, 5, 8, 11 — a = 2, d = 3. 4-had 11, yig‘indi 2 + 5 + 8 + 11 = 26.