KTLT-chuong7.c

#include <stdio.h>
#include <math.h>
#include <stdbool.h>

char Lowercase(char c) {
    // A to Z only
    char uppercase = (int)c;
    if (uppercase >= 65 && uppercase <= 90) uppercase += 32;
    return uppercase; //printf("%c")
}

void SolveLinear(float a, float b) {
    if (a != 0) printf("x = %f", (-1)*b/a);
    else {
        if (b == 0) printf("infinite solutions");
        else printf("no solution");
    }
}

void SolveQuadratic(float a, float b, float c) {
    if (a == 0) SolveLinear(b, c);
    else {
        float delta = b*b - 4*a*c;
        if (delta > 0) {
            printf("x1 = %f\n", ((-1)*b + sqrt(delta)) / (2*a));
            printf("x2 = %f\n", ((-1)*b - sqrt(delta)) / (2*a));
        }
        else if (delta == 0) printf("x = %f", ((-1)*b) / (2*a));
        else printf("no real solution");
    }
}

int Min(int a, int b) {
    if (a < b) return a;
    else return b;
}
int Min4(int a, int b, int c, int d) {
    return Min(Min(a, b), Min(c, d));
}

// B6

int ReverseNumber(int n) {
    int reversed = 0;
    for (; n>0; n/=10) {
        reversed *= 10;
        reversed += n % 10;
    }
    return reversed;
}

int SumOddDigit(int n) {
    int sum = 0;
    for (; n>0; n/=10) {
        if ((n % 10) % 2 != 0) sum += n % 10;
    }
    return sum;
}

bool KTChinhPhuong(int n) {
    return sqrt(n) == floor(sqrt(n));
}

bool KTNguyenTo(int n) {
    if (n == 1) return false;
    if (n == 2) return true;
    for (int i = 2; i <= sqrt(n); i++) {
        if (n % i == 0) return false;
    }
    return true;
}

    
int main() {
    return 0;
}