Created
August 6, 2024 20:26
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Leetcode 120. Triangle
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| # top-down: Larger Number TLE | |
| class Solution: | |
| def minimumTotal(self, triangle: List[List[int]]) -> int: | |
| if len(triangle) == 1: | |
| return triangle[0][0] | |
| res = tuple() | |
| level = 0 | |
| curr_list = triangle[level] | |
| next_level = level + 1 | |
| next_list = triangle[next_level] | |
| for idx in range(next_level): | |
| for offset, each_num in enumerate(next_list[idx:idx+2]): | |
| res += (self.doMinTotal(each_num + curr_list[idx], offset+idx, next_level, triangle),) | |
| return min(res) | |
| def doMinTotal(self, ans: int, start_idx: int, level: int, triangle: List[List[int]]) -> int: | |
| next_level = level + 1 | |
| if next_level == len(triangle): | |
| return ans | |
| res = tuple() | |
| next_list = triangle[next_level] | |
| for offset, each_num in enumerate(next_list[start_idx:start_idx+2]): | |
| res += (self.doMinTotal(ans + each_num, start_idx + offset, next_level, triangle),) | |
| return min(res) | |
| # Bottom-up, Efficient | |
| class Solution: | |
| def minimumTotal(self, triangle: List[List[int]]) -> int: | |
| if len(triangle) == 1: | |
| return triangle[0][0] | |
| for level in range(len(triangle) - 1, 0, -1): | |
| curr_list = triangle[level] | |
| prev_list: List[int] = triangle[level-1] | |
| for idx in range(level): | |
| triangle[level-1][idx] += min(curr_list[idx: idx+2]) | |
| return triangle[0][0] |
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