106 lines
2.4 KiB
C
106 lines
2.4 KiB
C
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#include "types.h"
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#include <math.h>
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#include <stdbool.h>
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#include <stdio.h>
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void read_print_quadratic() {
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// TODO 1. Read 3 numbers: a, b and c which represent known numbers for
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// quadratic equation in standard format (ax^2 + bx + c = 0) from stdin.
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printf("Enter numbers a, b and c of equation ax^2 +bx + c = 0:\n");
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int a, b, c;
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scanf("%d %d %d", &a, &b, &c);
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// TODO 2. Check if equation is quadratic. If so, calculate its discriminant
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// and, if possible, print all roots to stdout.
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if (a == 0 || (a == 0 && b == 0 && c == 0)) {
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printf("Please enter a cooler formula");
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return;
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}
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double d = b * b + (-4) * a * c;
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printf("Discriminant: %.2f\n", d);
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if (d < 0) {
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printf("Discriminant is lower than 0, cannot solve equation in R");
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return;
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}
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double rootA, rootB;
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rootA = (-b + sqrt(d)) / (2*a);
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rootB = (-b - sqrt(d)) / (2*a);
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if (rootA == rootB) {
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printf("Equation has one solution: %.2f", rootA);
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} else {
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printf("Equation has two solution: %.2f and %.2f", rootA, rootB);
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}
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return;
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}
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void read_print_is_character() {
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// TODO 1. Read one character from stdin.
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printf("Enter a character:\n");
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char l;
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scanf(" %c", &l);
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// TODO 2. Determine whether the character represents a letter (a-z, A-Z) or
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// not and print the result to stdout.
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if ((l >= 'a' && l <= 'z') || (l >= 'A' && l <= 'Z')) {
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printf("%c IS a letter (a-z or A-Z)", l);
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} else {
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printf("%c is NOT a letter (a-z or A-Z)", l);
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}
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return;
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}
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void read_print_factorial() {
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printf("Enter a number for calcuation of factorial:\n");
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// TODO 1. Read one number from stdin.
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int a;
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scanf("%d", &a);
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// TODO 2. Print its factorial (!) to stdout.
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for (int i = a - 1; i != 0; --i) {
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a *= i;
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}
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printf("Factorial: %d", a);
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return;
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}
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void read_print_gcd() {
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// TODO 1. Read two numbers from stdin.
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printf("Enter two numbers to calculate gcd:\n");
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int a, b;
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scanf("%d %d", &a, &b);
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// see https://en.wikipedia.org/wiki/Greatest_common_divisor#Euclidean_algorithm
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while (b != 0) {
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int temp = b;
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b = a % b;
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a = temp;
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}
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printf("gcd is %d\n", a);
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return;
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}
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#ifndef TEST_BUILD
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int main() {
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printf("\n--read_print_quadratic--\n");
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read_print_quadratic();
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printf("\n--read_print_is_character--\n");
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read_print_is_character();
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printf("\n--read_print_factorial--\n");
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read_print_factorial();
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printf("\n--read_print_gcd--\n");
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read_print_gcd();
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return 0;
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}
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#endif
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