include <stdio.h>
include <stdlib.h>
// 結構體定義
typedef struct {
int* data; // 整數資料
int size; // 資料長度
int index; // 當前索引
} NestedIterator;
// 主函式:扁平化巢狀列表
int* flatten(int** nestedList, int nestedListSize, int* nestedListColSize, int* returnSize) {
// 計算扁平化後的結果長度
int totalSize = 0;
for (int i = 0; i < nestedListSize; i++) {
totalSize += nestedListColSize[i];
}
// 分配記憶體空間
int* result = (int*)malloc(totalSize * sizeof(int));
// 使用棧來處理元素
int* stack = (int*)malloc(totalSize * sizeof(int));
int top = -1;
// 將所有列表元素壓入棧中
for (int i = nestedListSize - 1; i >= 0; i--) {
for (int j = nestedListColSize[i] - 1; j >= 0; j--) {
stack[++top] = nestedList[i][j];
}
}
// 彈出棧頂元素並處理
int index = 0;
while (top >= 0) {
int item = stack[top--];
if (item >= 0) {
result[index++] = item; // 如果是整數,則新增到結果中
} else {
// 如果是列表,則將其元素逆序壓入棧中
for (int i = nestedListColSize[-item - 1] - 1; i >= 0; i--) {
stack[++top] = nestedList[-item - 1][i];
}
}
}
*returnSize = totalSize;
free(stack);
return result;
}
int main() {
int nestedList1[] = {1, 2, 3};
int nestedList2[] = {4, 5};
int nestedList3[] = {6};
int* nestedList[] = {nestedList1, nestedList2, nestedList3};
int nestedListSize = 3;
int nestedListColSize[] = {3, 2, 1};
int returnSize = 0;
int* flattenedList = flatten(nestedList, nestedListSize, nestedListColSize, &returnSize);
printf("Flattened List: ");
for (int i = 0; i < returnSize; i++) {
printf("%d ", flattenedList[i]);
}
printf("\n");
free(flattenedList);
return 0;
}