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48 lines
969 B
48 lines
969 B
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递归相关
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#### [10- I. 斐波那契数列](https://leetcode-cn.com/problems/fei-bo-na-qi-shu-lie-lcof/)
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```java
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class Solution {
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public int fib(int n) {
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if (n == 0 || n == 1) {
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return n;
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}
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int start = 0;
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int end = 1;
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int result = 0;
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for (int i = 2; i <= n; i++) {
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result = (start + end) % 1000000007;
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start = end;
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end = result;
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}
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return result;
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}
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}
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```
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#### [10- II. 青蛙跳台阶问题](https://leetcode-cn.com/problems/qing-wa-tiao-tai-jie-wen-ti-lcof/)
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```java
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class Solution {
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public int numWays(int n) {
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int result = 0;
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int start = 1;
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int end = 1;
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if (n == 0 || n == 1) {
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return 1;
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}
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for (int i = 2; i <= n; i++) {
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result = (start + end) % 1000000007;
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start = end;
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end = result;
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}
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return result;
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}
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}
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```
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