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Diffstat (limited to 'combination_sum2.c')
-rw-r--r-- | combination_sum2.c | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/combination_sum2.c b/combination_sum2.c new file mode 100644 index 0000000..6d20d09 --- /dev/null +++ b/combination_sum2.c @@ -0,0 +1,60 @@ +// 40. Combination Sum II +#include "leetcode.h" + +/* + * given a collection of candidate numbers and a target number, find all unique + * combinations in 'candidates' where the candidate numbers sum to 'target'. + * each number in 'candidates' may only be used once + */ + +int cmp(const void *a, const void *b) { return *(int *)a - *(int *)b; } + +void dfs(int *candidates, int candidatesSize, int target, int idx, int *curr, + int currSize, int *returnSize, int **returnColumnSizes, int ***res) { + int prev = 0; + for (int i = idx; i < candidatesSize; i++) { + if (candidates[i] == target) { + (*returnSize)++; + *res = (int **)realloc(*res, (*returnSize) * sizeof(int *)); + (*res)[(*returnSize) - 1] = (int *)malloc((currSize + 1) * sizeof(int)); + memcpy((*res)[(*returnSize) - 1], curr, currSize * sizeof(int)); + (*res)[(*returnSize) - 1][currSize] = candidates[i]; + (*returnColumnSizes) = + (int *)realloc((*returnColumnSizes), (*returnSize) * sizeof(int)); + (*returnColumnSizes)[(*returnSize) - 1] = currSize + 1; + break; + } else if (candidates[i] <= (target / 2) && candidates[i] != prev) { + curr[currSize] = candidates[i]; + dfs(candidates, candidatesSize, target - candidates[i], i + 1, curr, + currSize + 1, returnSize, returnColumnSizes, res); + prev = candidates[i]; + } else if (candidates[i] > target) + break; + } +} + +int **combinationSum2(int *candidates, int candidatesSize, int target, + int *returnSize, int **returnColumnSizes) { + qsort(candidates, candidatesSize, sizeof(int), cmp); + int *curr = (int *)malloc(100 * sizeof(int)), currSize = 0; + int **ans = (int **)malloc(sizeof(int *)); + (*returnColumnSizes) = (int *)malloc(sizeof(int)); + (*returnSize) = 0; + dfs(candidates, candidatesSize, target, 0, curr, currSize, returnSize, + returnColumnSizes, &ans); + free(curr); + return ans; +} + +int main() { + int c1[] = {10, 1, 2, 7, 6, 1, 5}, c2[] = {2, 5, 2, 1, 2}, rs1, rs2; + int *rcs1 = (int *)malloc(ARRAY_SIZE(c1) * sizeof(int)); + int *rcs2 = (int *)malloc(ARRAY_SIZE(c2) * sizeof(int)); + int **cs21 = combinationSum2(c1, ARRAY_SIZE(c1), 8, &rs1, (int **)rcs1); + int **cs22 = combinationSum2(c2, ARRAY_SIZE(c2), 5, &rs2, (int **)rcs2); + for (int i = 0; i < rs2; i++) + for (int j = 0; j < rcs2[i]; j++) + printf("%d ", cs22[i][j]); + printf("\n"); + free(cs21), free(cs22), free(rcs1), free(rcs2); +} |