Calculate the factorial of n
recursion
//使用递归计算n的阶乘
#include<stdio.h>
int Jiecheng(int n)
{
if (n<=1)
{
return 1;
}
else
{
return n * Jiecheng(n - 1);
}
}
int main()
{
int n = 0;
scanf("%d", &n);
int ret = Jiecheng(n);
printf("%d", ret);
return 0;
}
The red line is the call, the blue line is the return value.
The recursive execution process can be seen more clearly through the above picture.
cycle
int Jiecheng(int n)
{
int count = 1;
while (n>1)
{
count = count * n;
n--;
}
return count;
}
int main()
{
int n = 0;
scanf("%d", &n);
int ret = Jiecheng(n);
printf("%d", ret);
return 0;
}
Find the nth Fibonacci number. (overflow is not considered)
recursion
#include<stdio.h>
int Fib(int n)
{
if (n>=3)
{
return Fib(n - 1) + Fib(n - 2);
}
else
{
return 1;
}
}
int main()
{
int n = 0;
scanf("%d", &n);
int ret = Fib(n);
printf("%d", ret);
return 0;
}
cycle
#include<stdio.h>
int Fib(int n)
{
int a = 1;
int b = 1;
int c = 1;
while (n>2)
{
c = a + b;
a = b;
b = c;
n--;
}
return c;
}
int main()
{
int n = 0;
scanf("%d", &n);
int ret = Fib(n);
printf("%d", ret);
return 0;
}
This blog mainly introduces how to use recursion and loops to solve problems, hoping to help you understand recursion and loops better.