You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
hello-algo/codes/c/chapter_backtracking/subset_sum_i_naive.c

70 lines
1.8 KiB

This file contains ambiguous Unicode characters!

This file contains ambiguous Unicode characters that may be confused with others in your current locale. If your use case is intentional and legitimate, you can safely ignore this warning. Use the Escape button to highlight these characters.

/**
* File: subset_sum_i_naive.c
* Created Time: 2023-07-28
* Author: Gonglja (glj0@outlook.com)
*/
#include "../utils/common.h"
#define MAX_SIZE 100
#define MAX_RES_SIZE 100
// 状态(子集)
int state[MAX_SIZE];
int stateSize = 0;
// 结果列表(子集列表)
int res[MAX_RES_SIZE][MAX_SIZE];
int resColSizes[MAX_RES_SIZE];
int resSize = 0;
/* 回溯算法:子集和 I */
void backtrack(int target, int total, int *choices, int choicesSize) {
// 子集和等于 target 时,记录解
if (total == target) {
for (int i = 0; i < stateSize; i++) {
res[resSize][i] = state[i];
}
resColSizes[resSize++] = stateSize;
return;
}
// 遍历所有选择
for (int i = 0; i < choicesSize; i++) {
// 剪枝:若子集和超过 target ,则跳过该选择
if (total + choices[i] > target) {
continue;
}
// 尝试:做出选择,更新元素和 total
state[stateSize++] = choices[i];
// 进行下一轮选择
backtrack(target, total + choices[i], choices, choicesSize);
// 回退:撤销选择,恢复到之前的状态
stateSize--;
}
}
/* 求解子集和 I包含重复子集 */
void subsetSumINaive(int *nums, int numsSize, int target) {
resSize = 0; // 初始化解的数量为0
backtrack(target, 0, nums, numsSize);
}
/* Driver Code */
int main() {
int nums[] = {3, 4, 5};
int numsSize = sizeof(nums) / sizeof(nums[0]);
int target = 9;
subsetSumINaive(nums, numsSize, target);
printf("输入数组 nums = ");
printArray(nums, numsSize);
printf("target = %d\n", target);
printf("所有和等于 %d 的子集 res = \n", target);
for (int i = 0; i < resSize; i++) {
printArray(res[i], resColSizes[i]);
}
return 0;
}