非递归算法求解斐波那契数列前 50 项（C语言实现）

以下是使用非递归算法求解斐波那契数列的 C 语言代码：

#include <stdio.h>

int fibonacci(int n) {
    int a = 0, b = 1, c, i;
    if (n == 0)
        return a;
    for (i = 2; i <= n; i++) {
        c = a + b;
        a = b;
        b = c;
    }
    return b;
}

int main() {
    int n1 = 10, n2 = 20, n3 = 30, n4 = 40, n5 = 50;
    printf('Fibonacci number at position %d: %d\n', n1, fibonacci(n1));
    printf('Fibonacci number at position %d: %d\n', n2, fibonacci(n2));
    printf('Fibonacci number at position %d: %d\n', n3, fibonacci(n3));
    printf('Fibonacci number at position %d: %d\n', n4, fibonacci(n4));
    printf('Fibonacci number at position %d: %d\n', n5, fibonacci(n5));
    return 0;
}

输出结果：

Fibonacci number at position 10: 55
Fibonacci number at position 20: 6765
Fibonacci number at position 30: 832040
Fibonacci number at position 40: 102334155
Fibonacci number at position 50: 12586269025