斐波拉契数列I
斐波那契数列示例:
1,1,2,3,5,8,13,21,34 。。。。
实现这样一个函数,得到斐波拉契数列指定位置上的值
迭代
js
/**
* 求斐波拉契数列第n项
* @param {number} index
* @returns {number}
*/
function fib(index) {
let a = 1, b = 1, c = 0
if (index === 1 || index === 2) {
return 1
}
while (index-- > 2) {
c = a + b
a = b
b = c
}
return c
};
/**
* 求斐波拉契数列第n项
* @param {number} index
* @returns {number}
*/
function fib(index) {
let a = 1, b = 1, c = 0
if (index === 1 || index === 2) {
return 1
}
while (index-- > 2) {
c = a + b
a = b
b = c
}
return c
};
递归
js
/**
* 求斐波拉契数列第n项
* @param {number} index
* @returns {number}
*/
function fib(index) {
if (index === 1 || index === 2) {
return 1
}
return fib(index - 1) + fib(index - 2)
};
/**
* 求斐波拉契数列第n项
* @param {number} index
* @returns {number}
*/
function fib(index) {
if (index === 1 || index === 2) {
return 1
}
return fib(index - 1) + fib(index - 2)
};