Merge branch 'master' of ssh://git.xwyam.tech:29226/xwyam/demo

reverse_linked_number.c

@@ -0,0 +1,63 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+typedef struct _st_node {
+    struct _st_node *next;
+    int val;
+} st_node;
+
+
+st_node *node_alloc(int val, st_node *next)
+{
+    st_node *node = (st_node *)malloc(sizeof (st_node));
+    node->next = next;
+    node->val = val;
+    return node;
+}
+
+st_node *node_sum_r(int carry_up, st_node *p, st_node *q)
+{
+    if (p) carry_up += p->val;
+    if (q) carry_up += q->val;
+    if (!p && !q && !carry_up) return 0;
+    return node_alloc(carry_up % 10,
+                        node_sum_r(carry_up / 10,
+                                    p ? p->next : 0,
+                                    q ? q->next : 0));
+}
+
+st_node *node_sum(st_node *p, st_node *q)
+{
+    if (!p || !q) return 0;
+    return node_sum_r(0, p, q);
+}
+
+st_node *str_to_node(char *num)
+{
+    if (!*num) return 0;
+    return node_alloc(*num - '0', str_to_node(num + 1));
+}
+
+void node_show_r(st_node *node)
+{
+    if (!node) return;
+    node_show_r(node->next);
+    printf("%d", node->val);
+    return;
+}
+
+void node_show(st_node *node)
+{
+    node_show_r(node);
+    printf("\n");
+    return;
+}
+
+int main()
+{
+    st_node *l1 = str_to_node("99");
+    st_node *l2 = str_to_node("9999");
+    st_node *ls = node_sum(l1, l2);
+    node_show(ls);
+    return 0;
+}