function fibonacci(n) { if(n === 1 || n === 2) { return 1 } else { let pre2 = 1 let pre1 = 1 let summary = 0 for(let i = 3; i <= n; i++) { summary = pre2 + pre1 pre2 = pre1 pre1 = summary } return summary } }
function fibonacci(n) { if(n === 1 || n === 2) { return 1 } else { let pre2 = 1 let pre1 = 1 let summary = 0 for(let i = 3; i <= n; i++) { summary = pre2 + pre1 pre2 = pre1 pre1 = summary } return summary } }