用自定义函数求出斐波那契数列的下一项

img


明明是很基础的东西，但我还是觉得C语言好难学啊
凑够三十个字好难啊

#include<stdio.h>
int fun(int t)
{
    int a = 1, b = 1,c;
    c = a + b;
    for (int i = 2; c <= t; i++)
    {
        c = a + b;
        a = b;
        b = c;
    }
    return c;
}
int main()
{
    int n;
    printf("Input n please:");
    scanf("%d", &n);
    printf("n=%d,f=%d\n", n, fun(n));
    return 0;
}