diff options
author | Jack Sangdahl <[email protected]> | 2025-01-04 23:04:08 +0100 |
---|---|---|
committer | Jack Sangdahl <[email protected]> | 2025-01-04 23:04:08 +0100 |
commit | 2a8a768249be900c9946204b45519ebacbb9b485 (patch) | |
tree | 405f6323a08df6d0055fcec779c28b305e2803c6 /max_side_length_square.c | |
parent | b5f958e92ce7384d273271d8c594c4bb45a8c6fe (diff) | |
download | leetcode-2a8a768249be900c9946204b45519ebacbb9b485.tar.gz leetcode-2a8a768249be900c9946204b45519ebacbb9b485.zip |
1292. maximum side length of a square with sum less than or equal to threshold
Diffstat (limited to 'max_side_length_square.c')
-rw-r--r-- | max_side_length_square.c | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/max_side_length_square.c b/max_side_length_square.c new file mode 100644 index 0000000..5c6e701 --- /dev/null +++ b/max_side_length_square.c @@ -0,0 +1,53 @@ +// 1292. Maximum Side Length of a Square with Sum Less than or Equal to +// Threshold +#include "leetcode.h" + +/* + * given a 'm x n' matrix 'mat' and an integer 'threshold', return the maximum + * side-length of a square with a sum less than or equal to 'threshold' or + * return 0 if there is no such square. + */ + +int maxSideLength(int **mat, int matSize, int *matColSize, int threshold) { + int w = matSize, h = matColSize[0], prefix[w][h]; + for (int x = 0; x < w; x++) + for (int y = 0; y < h; y++) + prefix[x][y] = mat[x][y] + (x ? prefix[x - 1][y] : 0) + + (y ? prefix[x][y - 1] : 0) - + (x && y ? prefix[x - 1][y - 1] : 0); + int max = w > h ? w : h, best = -1; + for (int s = 0; s < max; s++) { + for (int x = 0; x < w - s; x++) { + for (int y = 0; y < h - s; y++) { + int sum = prefix[x + s][y + s] - (x ? prefix[x - 1][y + s] : 0) - + (y ? prefix[x + s][y - 1] : 0) + + (x && y ? prefix[x - 1][y - 1] : 0); + if (sum <= threshold) { + best = s; + break; + } + } + if (best == s) + break; + } + if (best != s) + break; + } + return best + 1; +} + +int main() { + int m1i[3][7] = { + {1, 1, 3, 2, 4, 3, 2}, {1, 1, 3, 2, 4, 3, 2}, {1, 1, 3, 2, 4, 3, 2}}; + int m2i[4][5] = { + {2, 2, 2, 2, 2}, {2, 2, 2, 2, 2}, {2, 2, 2, 2, 2}, {2, 2, 2, 2, 2}}; + struct two_d_arr m1, m2; + two_d_arr_init(&m1, 3, 7, m1i); + two_d_arr_init(&m2, 4, 5, m2i); + printf("%d\n", + maxSideLength(m1.arr, m1.row_size, m1.col_size, 4)); // expect: 2 + printf("%d\n", + maxSideLength(m2.arr, m2.row_size, m2.col_size, 1)); // expect: 0 + two_d_arr_free(&m1); + two_d_arr_free(&m2); +} |