wtf bro

main.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <conio.h>
#include <math.h>

void sapXep(float arr[], int n);
void inKetQua(float arr[], int n);
void prog1();
void SaoChep(char *ChuoiNguon, char *ChuoiDich, int ViTri, int SoKyTu);
void prog2();
void prog3();

int main(){
    printf("BAI TAP CA NHAN GIUA KY\n");
    printf("DANG TRUNG NHAN - B2207483\n");
    printf("Bai tap so 3\n");
    printf("===========================\n");

    int p;
    printf("Vui long chon chuong trinh con:\n");
    printf("1. Mang, sap xep mang va chen them phan tu\n");
    printf("2. Ham sao chep du lieu su dung chuoi duoi dang con tro ky tu\n");
    printf("3. Su dung kieu cau truc cho tam giac\n");
    printf("Lua chon: ");
    scanf("%d", &p);
    getchar();

    switch (p) {
        case 1:
            prog1();
            break;
        case 2:
            prog2();
            break;
        case 3:
            prog3();
            break;
        default:
            printf("Khong nhan dang duoc yeu cau, dang dung chuong trinh...\n");
            break;
    }
    
    return 0;
}

void sapXep(float arr[], int n){
    int i, j;
    for (i = 0; i < n - 1; ++i) {
        for (j = 0; j < n - i - 1; ++j) {
            if (arr[j] < arr[j + 1]){
                float t = arr[j];
                arr[j] = arr[j + 1];
                arr[j + 1] = t;
            }
        }
    }
}

void inKetQua(float arr[], int n){
    int i;
    printf("Mang nhan duoc: [");
    for (i = 0; i < n; i++) {
        if (i < n - 1){
            printf("%g, ", arr[i]);
        } else {
            printf("%g", arr[i]);
        }
    }
    printf("]\n");

    sapXep(arr, n);

    printf("Mang sau khi sap xep giam dan: [");
    for (i = 0; i < n; i++) {
        if (i < n - 1){
            printf("%g, ", arr[i]);
        } else {
            printf("%g", arr[i]);
        }
    }
    printf("]\n");
}

void prog1(){
    int i, n;
    float arr[100];
    printf("Mang co bao nhieu phan tu: ");
    scanf(" %d", &n);


    for (i = 0; i < n; ++i) {
        printf("Nhap gia tri phan tu thu %d: ", i + 1);
        scanf("%f", &arr[i]);
    }

    inKetQua(arr, n);

    float ins;
    printf("Nhap so can chen vao mang: ");
    scanf("%f", &ins);

    n++;
    arr[n - 1] = ins;

    inKetQua(arr, n);

}

void SaoChep(char *ChuoiNguon, char *ChuoiDich, int ViTri, int SoKyTu) {
    int i;
    
    while (ViTri > 1 && *ChuoiNguon != '\0') {
        ChuoiNguon++;
        ViTri--;
    }
    
    for (i = 0; i < SoKyTu && *ChuoiNguon != '\0'; i++) {
        *ChuoiDich = *ChuoiNguon;
        ChuoiNguon++;
        ChuoiDich++;
    }
    *ChuoiDich = '\0';
}

void prog2() {
    char ChuoiNguon[100];
    char ChuoiDich[70];
    int ViTri, SoKyTu;
    
    printf("Nhap chuoi nguon: ");
    gets(ChuoiNguon);
    
    printf("Nhap vi tri bat dau sao chep: ");
    scanf("%d", &ViTri);
    
    printf("Nhap so ky tu can sao chep: ");
    scanf("%d", &SoKyTu);
    
    getchar();

    SaoChep(ChuoiNguon, ChuoiDich, ViTri, SoKyTu);
    printf("Ket qua chuoi dich: %s\n", ChuoiDich);
}

typedef struct{
    float canhA;
    float canhB;
    float canhC;
} tamGiac;

void prog3(){
    tamGiac TG;
    printf("Nhap do dai canh a: ");
    scanf("%f", &TG.canhA);
    
    printf("Nhap do dai canh b: ");
    scanf("%f", &TG.canhB);

    printf("Nhap do dai canh c: ");
    scanf("%f", &TG.canhC);
	getchar();
	
    if (TG.canhA + TG.canhB > TG.canhC && TG.canhA + TG.canhC > TG.canhB && TG.canhB + TG.canhC > TG.canhA){
        float chuVi = TG.canhA + TG.canhB + TG.canhC;
    	float p = chuVi / 2;
    	float dienTich = sqrt(p * (p - TG.canhA)*(p - TG.canhB)*(p - TG.canhC));
    	
    	printf("Chu vi cua tam giac la: %.2f\n", chuVi);
    	printf("Dien tich cua tam giac la: %.2f ", dienTich);
    } else{
        printf("Ba do dai nay khong the tao nen mot tam giac!\n");
    }
}