Sword Finger Offer 10- II. The problem of frog jumping
Title description
Problem-solving ideas
This question is 斐波那契数列
a variant.
class Solution {
public int numWays(int n) {
if (n == 0 || n == 1) return 1;
if (n == 2) return 2;
//base case
int dp_0 = 1, dp_1 = 2;
int res = -1;
for (int i = 3; i <= n; i++) {
res = (dp_0 + dp_1) % 1000000007;
dp_0 = dp_1;
dp_1 = res;
}
return res;
}
}