diff options
Diffstat (limited to 'other/num_ways_remain_place.cpp')
-rw-r--r-- | other/num_ways_remain_place.cpp | 32 |
1 files changed, 0 insertions, 32 deletions
diff --git a/other/num_ways_remain_place.cpp b/other/num_ways_remain_place.cpp deleted file mode 100644 index eee14e5..0000000 --- a/other/num_ways_remain_place.cpp +++ /dev/null @@ -1,32 +0,0 @@ -// 1269. Number of Ways to Stay in the Same Place After Some Steps -#include "leetcode.h" - -/* - * you have a pointer at index 0 in an array of size 'arr_len'. at each step, - * you can move 1 position to the left, 1 position to the right in the array, or - * stay in the same plae. given two integers 'steps' and 'arr_len' return the - * number of ways such that your pointer is still at index 0 after exactly - * 'steps' steps. since the answer may be too large, return it modulo 10e9+7 - */ - -class Solution { -public: - int numWays(int steps, int arr_len) { - int n = min(steps / 2 + 1, arr_len); - vector<int> v1(n + 2), v2(n + 2); - v1[1] = 1; - while (steps--) { - for (auto i = 1; i <= n; ++i) - v2[i] = ((long)v1[i] + v1[i - 1] + v1[i + 1]) % 1000000007; - swap(v1, v2); - } - return v1[1]; - } -}; - -int main() { - Solution obj; - printf("%d\n", obj.numWays(3, 2)); // expect: 4 - printf("%d\n", obj.numWays(2, 4)); // expect: 2 - printf("%d\n", obj.numWays(4, 2)); // expect: 8 -} |