Tất cả câu hỏi

int n;
char c;
scanf("%d", &n);
c = getchar();
printf("%d",c);

char str1[20] = "Hello";
char str2[20] = "World";
strcat(str1, str2);
printf("%s", str1);

int a[] = {1,2,3,4};
int i=0, s=0;
for (; a[i]; ++i)
    s += a[i];
printf("%d", s);

void swap(int *a, int *b) {
    int t = *a;
    *a = *b;
    *b = t;
}

int main() {
    int x = 5, y = 10;
    swap(&x, &y);
    printf("%d %d", x, y);
    return 0;
}

#include<stdio.h>
void updatePosition(int *time, float* position, float v)
{
    if ((*position < 5) && (*position > -5))
        *position += v;
    else
        *position += -0.1*(*position);
    time += 1;
}

main()
{
    float p = 4.0, v = 1;
    int t = 0;
    printf("t = %d, p = %f\n", t, p);
    updatePosition(&t, &p, v);
    updatePosition(&t, &p, v);
    printf("t = %d, p = %f\n", t, p);
}

char sentence[81] = "This is a test";
int n = strlen(sentence);
printf("%d", n);

#include <stdio.h>
#define MONTHS_IN_YEAR 12
int main() {
    const int WORKING_DAYS = 22;
    printf("%d ", MONTHS_IN_YEAR);
    printf("%d", WORKING_DAYS);
    return 0;
}