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Diffstat (limited to 'diagonal_traverse.c')
-rw-r--r-- | diagonal_traverse.c | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/diagonal_traverse.c b/diagonal_traverse.c new file mode 100644 index 0000000..802271d --- /dev/null +++ b/diagonal_traverse.c @@ -0,0 +1,57 @@ +// 498. Diagonal Traverse +#include "leetcode.h" + +/* + * given an 'm x n' matrix 'mat', return an array of all the elements of the + * array in a diagonal order. + */ + +int *findDiagonalOrder(int **mat, int matSize, int *matColSize, + int *returnSize) { + int n = matSize * matColSize[0], row = 0, col = 0; + int *ans = (int *)malloc(n * sizeof(int)); + *returnSize = n; + for (int i = 0; i < n; i++) { + ans[i] = mat[row][col]; + if (!((row + col) % 2)) { + if (col == matSize - 1) + row++; + else if (!row) + col++; + else { + row--; + col++; + } + } else { + if (row == matColSize[0] - 1) + col++; + else if (!col) + row++; + else { + row++; + col--; + } + } + } + return ans; +} + +int main() { + int m1i[3][3] = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}}, + m2i[2][2] = {{1, 2}, {3, 4}}; + struct two_d_arr m1, m2; + two_d_arr_init(&m1, ARRAY_SIZE(m1i), ARRAY_SIZE(m1i[0]), m1i); + two_d_arr_init(&m2, ARRAY_SIZE(m2i), ARRAY_SIZE(m2i[0]), m2i); + int rs1, *fdo1 = findDiagonalOrder(m1.arr, m1.row_size, m1.col_size, &rs1); + int rs2, *fdo2 = findDiagonalOrder(m2.arr, m2.row_size, m2.col_size, &rs2); + for (int i = 0; i < rs1; i++) + printf("%d ", fdo1[i]); // expect: 1 2 4 7 5 3 6 8 9 + printf("\n"); + for (int i = 0; i < rs2; i++) + printf("%d ", fdo2[i]); // expect: 1 2 3 4 + printf("\n"); + free(fdo1); + free(fdo2); + two_d_arr_free(&m1); + two_d_arr_free(&m2); +} |