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Diffstat (limited to 'works/solutions/cpp/746.cpp')
-rw-r--r-- | works/solutions/cpp/746.cpp | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/works/solutions/cpp/746.cpp b/works/solutions/cpp/746.cpp new file mode 100644 index 0000000..aea1891 --- /dev/null +++ b/works/solutions/cpp/746.cpp @@ -0,0 +1,35 @@ +#include <vector> + +using std::vector; + +#include <algorithm> + +class Solution +{ +public: + int minCostClimbingStairs(vector<int> &cost) + { + int count = cost.size(); + + // Total cost for index i means min cost of stepping through the number i stair, + // after which you are free to jump two or one stair. + // total_costs[i] is based on total_costs[i - 2] and total_costs[i - 1]. + // Note: + // This is not min cost to step above the number i stair, which has no simple dependency + // relationship because based on whether it steps through the last step there are two situation. + // However with the restriction of stepping through that last stair, there is a + // dependency relationship. And we can easily get the final result by comparing total_costs[count - 2] + // and total_costs[count - 1]. But not just use total_costs[count - 1]. + vector<int> total_costs(count); + + total_costs[0] = cost[0]; + total_costs[1] = cost[1]; + + for (int i = 2; i < count; i++) + { + total_costs[i] = std::min(total_costs[i - 2], total_costs[i - 1]) + cost[i]; + } + + return std::min(total_costs[count - 2], total_costs[count - 1]); + } +}; |