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authorJack Sangdahl <[email protected]>2025-08-01 12:56:20 +0100
committerJack Sangdahl <[email protected]>2025-08-01 12:56:20 +0100
commit0434a2a41dfb2a3b17f785cb07de16c5b09b0d56 (patch)
treedab7a3195fff16c580ea5a56be09c4f2367856e7
parent432f582bd1d66c3b87fd365846a620d4a4d9f8a8 (diff)
downloadleetcode-0434a2a41dfb2a3b17f785cb07de16c5b09b0d56.tar.gz
leetcode-0434a2a41dfb2a3b17f785cb07de16c5b09b0d56.zip
118. pascals triangle
-rw-r--r--pascals_triangle.c62
-rw-r--r--pascals_triangle.py13
2 files changed, 40 insertions, 35 deletions
diff --git a/pascals_triangle.c b/pascals_triangle.c
index 969bdf0..e5d0227 100644
--- a/pascals_triangle.c
+++ b/pascals_triangle.c
@@ -1,45 +1,51 @@
// 118. Pascal's Triangle
-#include <stdio.h>
-#include <stdlib.h>
+#include "leetcode.h"
/*
- * given an integer 'num_rows', return the first numrows of pascal's triangle.
+ * given an integer 'numRows', return the first numrows of pascal's triangle.
* in pascal's triangle, each number is the sum of the two number direction
* above it as show [gif]
*/
-int **generate(int num_rows, int *return_size, int **col_size) {
- int **ans = (int **)malloc(sizeof(int *) * num_rows);
- int i, j;
- *return_size = num_rows;
- for (i = 0; i < num_rows; i++) {
- ans[i] = (int *)malloc(sizeof(int) * (i + 1));
- ans[i][0] = 1;
- ans[i][i] = 1;
+int **generate(int numRows, int *returnSize, int **returnColumnsSizes) {
+ *returnSize = numRows;
+ int **ans = (int **)calloc(1, sizeof(int *[numRows]));
+ *returnColumnsSizes = (int *)calloc(1, sizeof(int[numRows]));
+ for (int i = 0; i < numRows; i++) {
+ (*returnColumnsSizes)[i] = i + 1;
+ ans[i] = (int *)calloc(1, sizeof(int[i + 1]));
}
- *col_size = (int *)malloc(sizeof(int) * num_rows);
- for (i = 0; i < num_rows; i++)
- (*col_size)[i] = i + 1;
- i = 2;
- while (i < num_rows) {
- j = 1;
- while (j < i) {
+ ans[0][0] = 1;
+ for (int i = 1; i < numRows; i++) {
+ ans[i][0] = 1;
+ for (int j = 1; j < i; j++)
ans[i][j] = ans[i - 1][j - 1] + ans[i - 1][j];
- j++;
- }
- i++;
+ ans[i][i] = 1;
}
return ans;
}
int main() {
- int **g1 = generate(5, NULL, NULL);
- int **g2 = generate(1, NULL, NULL);
- for (int i = 0; i < 5; i++)
- for (int j = 0; j < 5; j++)
+ int rs1, *rcs1, **g1 = generate(5, &rs1, &rcs1);
+ int rs2, *rcs2, **g2 = generate(1, &rs2, &rcs2);
+ for (int i = 0; i < rs1; i++) {
+ for (int j = 0; j < rcs1[i]; j++)
printf("%d ",
g1[i][j]); // expect: [[1],[1,1],[1,2,1],[1,3,3,1],[1,4,6,4,1]]
- for (int i = 0; i < 1; i++)
- for (int j = 0; j < 1; j++)
- printf("%d ", g2[i][j]); // expect: [[1]]
+ printf("\n");
+ }
+ printf("\n");
+ for (int i = 0; i < rs2; i++) {
+ for (int j = 0; j < rcs2[i]; j++)
+ printf("%d ",
+ g2[i][j]); // expect: [[1]]
+ printf("\n");
+ }
+ printf("\n");
+ for (int i = 0; i < rs1; i++)
+ free(g1[i]);
+ free(g1), free(rcs1);
+ for (int i = 0; i < rs2; i++)
+ free(g2[i]);
+ free(g2), free(rcs2);
}
diff --git a/pascals_triangle.py b/pascals_triangle.py
index 0b2bf08..042f823 100644
--- a/pascals_triangle.py
+++ b/pascals_triangle.py
@@ -1,19 +1,18 @@
# 118. Pascal's Triangle
"""
-given an integer 'num_rows', return the first numrows of pascal's triangle.
+given an integer 'numRows', return the first numrows of pascal's triangle.
in pascal's triangle, each number is the sum of the two number direction
above it as show [gif]
"""
class Solution(object):
- def generate(self, num_rows):
- ans = [[1 for _ in range(row + 1)] for row in range(num_rows)]
- for row in range(num_rows):
- for col in range(1, row):
- ans[row][col] = ans[row - 1][col] + ans[row - 1][col - 1]
- return ans
+ def generate(self, numRows):
+ ans = [[1]]
+ for i in range(1, numRows):
+ ans += [map(lambda x, y: x + y, ans[-1] + [0], [0] + ans[-1])]
+ return ans[:numRows]
if __name__ == "__main__":