//遞歸寫法 long long FibonacciSeq(int n) { if (n < 2) { return n; } return FibonacciSeq(n - 1) + FibonacciSeq(n - 2); }
// 非遞歸(方法一) long long FibonacciSeq(int n) //可讀性差,效率高 { long long f[3] = { 0, 1,n }; for (int i = 2; i <=n; i++) { f[2] = f[0] + f[1]; f[0] = f[1]; f[1] = f[2]; } return f[2]; }
//(方法二) long long FibonacciSeq(int n) { long long fib[1000] = { 0, 1 }; //這裏不嚴謹,如果傳的參數大於1000就不好了 for (int i = 2; i <= n; i++) { fib[i] = fib[i - 1] + fib[i - 2]; } long long ret = fib[n]; return ret; }
///// (方法二的另一種寫法) long long FibonacciSeq( int n) { //這裏一定要判斷邊界條件,否則傳的參數爲0時,程序會因觸發斷點而崩潰 if (n ==0) { return 0; } long long *fib=new long long[n+1]; fib[0] = 0; fib[1] = 1; for (int i = 2;i <=n; i++) { fib[i] = fib[i - 1] + fib[i - 2]; } long long ret = fib[n]; delete[] fib; return ret; }
///// (方法二的另一種寫法) long long FibonacciSeq(int n) { if (n == 0) { return 0; } long long *fib = (long long *)malloc(sizeof(long long)*(n + 1)); fib[0] = 0; fib[1] = 1; for (int i = 2; i <= n; i++) { fib[i] = fib[i - 1] + fib[i - 2]; } long long ret = fib[n]; free(fib); return ret; }
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