Path sum

Signed-off-by: Leo Ma <[email protected]>

112_path_sum/Makefile

@@ -0,0 +1,2 @@
+all:
+	gcc -O2 -o test path_sum.c

112_path_sum/path_sum.c

@@ -0,0 +1,56 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+
+struct TreeNode {
+    int val;
+    struct TreeNode *left;
+    struct TreeNode *right;
+};
+
+static bool hasPathSum(struct TreeNode *root, int sum)
+{
+    if (root == NULL) {
+        return false;
+    } else if (root->left == NULL && root->right == NULL && root->val == sum) {
+        return true;
+    } else {
+        return hasPathSum(root->left, sum - root->val) || hasPathSum(root->right, sum - root->val);
+    }
+}
+
+int main(int argc, char **argv)
+{
+    struct TreeNode root, n1[2], n2[4], n3[8];
+    root.val = 5;
+    n1[0].val = 4;
+    n1[1].val = 8;
+    n2[0].val = 11;
+    n2[2].val = 13;
+    n2[3].val = 4;
+    n3[0].val = 7;
+    n3[1].val = 2;
+    n3[7].val = 1;
+
+    root.left = &n1[0];
+    root.right = &n1[1];
+    n1[0].left = &n2[0];
+    n1[0].right = NULL;
+    n1[1].left = &n2[2];
+    n1[1].right = &n2[3];
+    n2[0].left = &n3[0];
+    n2[0].right = &n3[1];
+    n2[2].left = NULL;
+    n2[2].right = NULL;
+    n2[3].left = NULL;
+    n2[3].right = &n3[7];
+    n3[0].left = NULL;
+    n3[0].right = NULL;
+    n3[1].left = NULL;
+    n3[1].right = NULL;
+    n3[7].left = NULL;
+    n3[7].right = NULL;
+
+    printf("%s\n", hasPathSum(&root, 22) ? "true" : "false");
+    return 0;
+}

113_path_sum_ii/Makefile

@@ -0,0 +1,2 @@
+all:
+	gcc -O2 -o test path_sum.c

113_path_sum_ii/path_sum.c

@@ -0,0 +1,91 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+struct TreeNode {
+    int val;
+    struct TreeNode *left;
+    struct TreeNode *right;
+};
+
+static void recursive(struct TreeNode *node, int sum, int *stack, int len, int **results, int *sizes, int *count)
+{
+    if (node == NULL) {
+        return;
+    }
+
+    sum -= node->val;
+    if (node->left == NULL && node->right == NULL && sum == 0) {
+        results[*count] = malloc((len + 1) * sizeof(int));
+        memcpy(results[*count], stack, len * sizeof(int));
+        results[*count][len] = node->val;
+        sizes[*count] = len + 1;
+        (*count)++;
+        return;
+    }
+    stack[len] = node->val;
+    recursive(node->left, sum, stack, len + 1, results, sizes, count);
+    recursive(node->right, sum, stack, len + 1, results, sizes, count);
+}
+
+static int **pathSum(struct TreeNode *root, int sum, int **columnSizes, int *returnSize)
+{
+    if (root == NULL) {
+        *returnSize = 0;
+        return NULL;
+    }
+
+    int level = 5000, cap = 1000;
+    int *stack = malloc(level * sizeof(int));
+    int **results = malloc(cap * sizeof(int *));
+    *columnSizes = malloc(cap * sizeof(int));
+    recursive(root, sum, stack, 0, results, *columnSizes, returnSize);
+    return results;
+}
+
+int main(int argc, char **argv)
+{
+    struct TreeNode root, n1[2], n2[4], n3[8];
+    root.val = 5;
+    n1[0].val = 4;
+    n1[1].val = 8;
+    n2[0].val = 11;
+    n2[2].val = 13;
+    n2[3].val = 4;
+    n3[0].val = 7;
+    n3[1].val = 2;
+    n3[6].val = 5;
+    n3[7].val = 1;
+
+    root.left = &n1[0];
+    root.right = &n1[1];
+    n1[0].left = &n2[0];
+    n1[0].right = NULL;
+    n1[1].left = &n2[2];
+    n1[1].right = &n2[3];
+    n2[0].left = &n3[0];
+    n2[0].right = &n3[1];
+    n2[2].left = NULL;
+    n2[2].right = NULL;
+    n2[3].left = &n3[6];
+    n2[3].right = &n3[7];
+    n3[0].left = NULL;
+    n3[0].right = NULL;
+    n3[1].left = NULL;
+    n3[1].right = NULL;
+    n3[6].left = NULL;
+    n3[6].right = NULL;
+    n3[7].left = NULL;
+    n3[7].right = NULL;
+
+    int i, j, count = 0;
+    int *sizes;
+    int **list = pathSum(&root, 22, &sizes, &count);
+    for (i = 0; i < count; i++) {
+        for (j = 0; j < sizes[i]; j++) {
+            printf("%d ", list[i][j]);
+        }
+        printf("\n");
+    }
+    return 0;
+}