C语言程序练习题7

#include <stdio.h>
#include <string.h>

int main() {
  char str[100], temp;
  int i, j;
  printf("Enter a string: ");
  scanf("%s", str);
  j = strlen(str) - 1;
  for (i = 0; i < j; i++, j--) {
    temp = str[i];
    str[i] = str[j];
    str[j] = temp;
  }
  printf("Reverse of the string: %s\n", str);
  return 0;
}

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

int main() {
  double num, root;
  printf("Enter a number: ");
  scanf("%lf", &num);
  root = sqrt(num);
  printf("Square root of %.2lf is %.2lf\n", num, root);
  return 0;
}

#include <stdio.h>

int fib(int n) {
  if (n == 0 || n == 1) {
    return n;
  } else {
    return fib(n - 1) + fib(n - 2);
  }
}

int main() {
  int n, i;
  printf("Enter the number of terms: ");
  scanf("%d", &n);
  for (i = 0; i < n; i++) {
    printf("%d ", fib(i));
  }
  printf("\n");
  return 0;
}

#include <stdio.h>

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

int main() {
  int a, b;
  printf("Enter two integers: ");
  scanf("%d%d", &a, &b);
  printf("Before swapping: a = %d, b = %d\n", a, b);
  swap(&a, &b);
  printf("After swapping: a = %d, b = %d\n", a, b);
  return 0;
}