Subsets

Signed-off-by: begeekmyfriend <[email protected]>

078_subsets/Makefile

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

078_subsets/subsets.c

@@ -0,0 +1,58 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+static void subset_recursive(int *nums, int size, int start,
+                             int *buf, int len,
+                             int **sets, int *sizes, int *count)
+{
+    int i;
+    sets[*count] = malloc(len * sizeof(int));
+    memcpy(sets[*count], buf, len * sizeof(int));
+    sizes[*count] = len;
+    (*count)++;
+    for (i = start; i < size; i++) {
+        buf[len++] = nums[i];
+        subset_recursive(nums, size, i + 1, buf, len, sets, sizes, count);
+        len--;
+    }
+}
+
+/**
+ ** Return an array of arrays of size *returnSize.
+ ** The sizes of the arrays are returned as *columnSizes array.
+ ** Note: Both returned array and *columnSizes array must be malloced, assume caller calls free().
+ **/
+int** subsets(int* nums, int numsSize, int** columnSizes, int* returnSize) {
+    int capacity = 5000;
+    int **sets = malloc(capacity * sizeof(int *));
+    int *buf = malloc(numsSize * sizeof(int));
+    *columnSizes = malloc(capacity * sizeof(int));
+    *returnSize = 0;
+    subset_recursive(nums, numsSize, 0, buf, 0, sets, *columnSizes, returnSize);
+    return sets;
+}
+
+int main(int argc, char **argv)
+{
+    int i, j;
+    if (argc <= 1) {
+        fprintf(stderr, "Usage: ./test array...\n");
+        exit(-1);
+    }
+    int size = argc - 1;
+    int *nums = malloc(size * sizeof(int));
+    for (i = 0; i < size; i++) {
+        nums[i] = atoi(argv[i + 1]);
+    }
+    int *sizes;
+    int count;
+    int **lists = subsets(nums, size, &sizes, &count);
+    for (i = 0; i < count; i++) {
+        for (j = 0; j < sizes[i]; j++) {
+            printf("%d ", lists[i][j]);
+        }
+        printf("\n");
+    }
+    return 0;
+}

090_subsets_ii/Makefile

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

090_subsets_ii/subsets.c

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+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+int *cache1, *cache2;
+
+static void insert_sort(int *nums, int size)
+{
+    int i, j;
+    for (i = 1; i < size; i++) {
+        int tmp = nums[i];
+        for (j = i - 1; j >= 0 && tmp < nums[j]; j--) {
+            nums[j + 1] = nums[j];
+        }
+        nums[j + 1] = tmp;
+    }
+}
+
+static int exist(int **results, int count, int *sizes, int *buf, int len)
+{
+    int i, j;
+    for (i = 0; i < count; i++) {
+        if (len == sizes[i]) {
+            memcpy(cache1, results[i], len * sizeof(int));
+            memcpy(cache2, buf, len * sizeof(int));
+            insert_sort(cache1, len);
+            insert_sort(cache2, len);
+            if (!memcmp(cache1, cache2, len * sizeof(int))) {
+                return 1;
+            }
+        }
+    }
+    return 0;
+}
+
+static void subset_recursive(int *nums, int size, int start,
+                             int *buf, int len,
+                             int **sets, int *sizes, int *count)
+{
+    int i;
+    if (!exist(sets, *count, sizes, buf, len)) {
+        sets[*count] = malloc(len * sizeof(int));
+        memcpy(sets[*count], buf, len * sizeof(int));
+        sizes[*count] = len;
+        (*count)++;
+    }
+    for (i = start; i < size; i++) {
+        buf[len++] = nums[i];
+        subset_recursive(nums, size, i + 1, buf, len, sets, sizes, count);
+        len--;
+    }
+}
+
+/**
+ ** Return an array of arrays of size *returnSize.
+ ** The sizes of the arrays are returned as *columnSizes array.
+ ** Note: Both returned array and *columnSizes array must be malloced, assume caller calls free().
+ **/
+int** subsets(int* nums, int numsSize, int** columnSizes, int* returnSize) {
+    int capacity = 5000;
+    int **sets = malloc(capacity * sizeof(int *));
+    int *buf = malloc(numsSize * sizeof(int));
+    *columnSizes = malloc(capacity * sizeof(int));
+    *returnSize = 0;
+    cache1 = malloc(numsSize * sizeof(int));
+    cache2 = malloc(numsSize * sizeof(int));
+    subset_recursive(nums, numsSize, 0, buf, 0, sets, *columnSizes, returnSize);
+    return sets;
+}
+
+int main(int argc, char **argv)
+{
+    int i, j;
+    if (argc <= 1) {
+        fprintf(stderr, "Usage: ./test array...\n");
+        exit(-1);
+    }
+    int size = argc - 1;
+    int *nums = malloc(size * sizeof(int));
+    for (i = 0; i < size; i++) {
+        nums[i] = atoi(argv[i + 1]);
+    }
+    int *sizes;
+    int count;
+    int **lists = subsets(nums, size, &sizes, &count);
+    for (i = 0; i < count; i++) {
+        for (j = 0; j < sizes[i]; j++) {
+            printf("%d ", lists[i][j]);
+        }
+        printf("\n");
+    }
+    return 0;
+}