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Diffstat (limited to 'min_path_sum.cpp')
-rw-r--r-- | min_path_sum.cpp | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/min_path_sum.cpp b/min_path_sum.cpp new file mode 100644 index 0000000..2240f59 --- /dev/null +++ b/min_path_sum.cpp @@ -0,0 +1,29 @@ +// 64. Minimum Path Sum +#include "leetcode.h" + +// given 'm x n grid' filled with non-negative numbers, find a path from top +// left to bottom right, which minimises the sum of all numbers along its path + +class Solution { +public: + int minPathSum(vvd(int) & grid) { + int m = grid.size(), n = grid[0].size(); + vvd(int) sum(m, vector<int>(n, grid[0][0])); + for (int i = 1; i < m; i++) + sum[i][0] = sum[i - 1][0] + grid[i][0]; + for (int j = 1; j < n; j++) + sum[0][j] = sum[0][j - 1] + grid[0][j]; + for (int i = 1; i < m; i++) + for (int j = 1; j < n; j++) + sum[i][j] = min(sum[i - 1][j], sum[i][j - 1]) + grid[i][j]; + return sum[m - 1][n - 1]; + } +}; + +int main() { + Solution obj; + vvd(int) g1 = {{1, 3, 1}, {1, 5, 1}, {4, 2, 1}}; + vvd(int) g2 = {{1, 2, 3}, {4, 5, 6}}; + printf("%d\n", obj.minPathSum(g1)); // expect: 7 + printf("%d\n", obj.minPathSum(g2)); // expect: 12 +} |