修改后,主要在put_in_bag函数,算法我也没去严格证明。。但改后比之前的要好一些,多谢@wmf2014前辈指教,调式输出先不删了,已备再改
程序代码:
#include<stdio.h>
#include<stdlib.h>
typedef struct Treasure{
struct Treasure * prev;
int weight;
struct Treasure * next;
} Treasure;
typedef struct Bag{
Treasure * header;
Treasure * tailer;
int weight;
}Bag;
int compare_treasure(const void *a, const void *b){ return ((Treasure *)a)->weight - ((Treasure *)b)->weight;}
void put_in_bag(int index);
void insert_to_bag(Bag *, Treasure *);
int n = 0;
int bag_capacity = 0;
Treasure *nodes = NULL; //
Bag **bags = NULL; //Treasure指针列表,列表以NULL结束
int main(void){
do {
printf("input num of treasures:");
scanf("%d", &n);
Treasure *pn = realloc(nodes, sizeof(*nodes) * n);
if (!pn) break;
nodes = pn;
Bag **pa = realloc(bags, sizeof(*bags)*(n+1));
if (!pa) break;
bags = pa;
printf("input capacity of bag:");
scanf("%d", &bag_capacity);
getchar();
printf("随机宝箱重量(y/n default to 'y'):");
int custom_input = getchar() == 'n';
if (custom_input)printf("input weight of treasures(<= capacity of bag):");
int weight;
int total_weight = 0;
for(int i = 0; i < n; ++i){
if (custom_input)
scanf("%d", &weight);
else
weight = rand() % n + 1;
if (weight > bag_capacity){
printf("error weight %d, 必须小于等于包裹容量\n", weight);
continue;
}
nodes[i].weight = weight;
nodes[i].next = nodes[i].prev = NULL;
total_weight += weight;
}
int count = total_weight % bag_capacity ? total_weight/bag_capacity + 1 : total_weight/bag_capacity;
//printf("-----%d\n", count);
for (int i = 0; i < count; ++i){
Bag * p = malloc(sizeof(Bag));
p->header = p->tailer = NULL;
p->weight = 0;
bags[i] = p;
bags[i+1] = NULL;
}
qsort(nodes, n, sizeof nodes[0], compare_treasure);
for(int i = 0; i < n; ++i)printf("%d ", nodes[i].weight);
put_in_bag(0);
for(int i = 0; bags[i]; ++i){
printf("\n%d *** [%d]:", i+1, bags[i]->weight);
Treasure *node = bags[i]->header;
for(; node; node=node->next)printf("%3d ", node->weight);
free(bags[i]);
bags[i] = NULL;
}
printf("\npress 'q' to quit, others to continue:\n");
if (custom_input)
while(getchar() != '\n');
}while(getchar() != 'q');
if (nodes) free(nodes);
if (bags) free(bags);
return 0;
}
void put_in_bag(int index){
if (index == n-1){
bags[0]->weight = nodes[index].weight; //头节点的weight表示整个链的总weight
bags[0]->header = bags[0]->tailer = nodes + index;
return;
}
put_in_bag(index + 1);
Treasure *node = &nodes[index];
int i = 0;
for (Bag *bag = bags[i]; bags[i]; bag = bags[++i]){
if (bag->weight + node->weight <= bag_capacity){
insert_to_bag(bag, node);
break;
}
}
if (!bags[i]){
Bag *bag0 = bags[0];
Treasure *tmp0 = bag0->tailer;
int as = 0, ai = 0;
while(tmp0){
as = bag_capacity - bag0->weight;
if (as >= node->weight){
insert_to_bag(bag0, node);
return;
}
// if (ai == tmp0->weight) continue;
ai = tmp0->weight;
//printf("\nai=%d as=%d \n", ai, as);
int j = 1;
for(Bag *bag = bags[j]; bags[j]; bag = bags[++j]){
Treasure *bm, *tmp;
int m = 0;
bm = bag->tailer;
for (tmp = bag->header; tmp; tmp = tmp->next){
if (tmp->weight >= ai){
bm = tmp->prev;
break;
}
++m;
}
//printf("\nm=%d bm=%p bmw=%d\n", m, bm, bm ?bm->weight:0);
if (m == 0 ) continue;
int bs = bag_capacity - bag->weight;
for (int k = 1; k <= m; ++k){
int bmin = 0, bmax = 0;
tmp = bag->header;
for (int p = 0; p < k; ++p){
bmin += tmp->weight;
tmp = tmp->next;
}
tmp = bm;
for (int p = 0; p < k; ++p){
bmax += tmp->weight;
tmp = tmp->prev;
}
//printf("\nbmin=%d, bmax=%d\n", bmin, bmax);
if (ai < bmin) continue;
if (ai > bmax) continue;
tmp = bag->header;
for (int q = 0; q < m-k+1; ++q){
Treasure *ttmp = tmp;
int bi = 0;
for(int p = 0; p < k; ++p){
bi += ttmp->weight;
ttmp = ttmp->next;
}
//printf(" bi=%d bs=%d ai=%d as=%d\n", bi, bs, ai, as);
if (bi+bs >= ai && bi <= as + ai){
if (tmp0->prev) tmp0->prev->next = tmp0->next;
else bag0->header = tmp0->next;
if (tmp0->next) tmp0->next->prev = tmp0->prev;
else bag0->tailer = tmp0->prev;
// for(Treasure *p = bag0->header; p; p = p->next) printf("%3d ", p->weight);
// printf("\n-- %d \n", tmp0->weight);
if(tmp->prev) tmp->prev->next = ttmp;
else bag->header = ttmp;
if (ttmp) ttmp->prev = tmp->prev;
bag0->weight -= ai;
bag->weight -= bi;
//for(Treasure *p = bag->header; p; p = p->next) printf("%3d ", p->weight);
// printf("\nc- %d %p %d\n", tmp->weight, ttmp, ttmp ? ttmp->weight : 0);
insert_to_bag(bag, tmp0);
// for(Treasure *p = bag->header; p; p = p->next) printf("%3d ", p->weight);
// printf("\n -3");
// while(getchar() != 'w');
for (Treasure *tp = tmp; tp != ttmp;){
Treasure * tp_ = tp->next; //insert之前调用
// printf(" %p %p \n", tp, ttmp);
insert_to_bag(bag0, tp);
tp = tp_;
}
//for(Treasure *p = bag->header; p; p = p->next) printf("%3d ", p->weight);
//printf("\n -4");
// while(getchar() != 'w');
tmp0 = NULL;
goto while_loop_end;//跳到while循环
}
tmp = tmp->next; //修改
} //for q
}//for k
}//for bag
while_loop_end: tmp0 = tmp0 ? tmp0->prev : bag0->tailer;
}//while
}// if
if (!bags[i]){
Bag * bag = (Bag *)malloc(sizeof(Bag)); //头节点
bag->header = bag->tailer = node;
bag->weight = node->weight;
bags[i] = bag;
bags[i+1] = NULL;
}
}
void insert_to_bag(Bag *bag, Treasure *treasure){
bag->weight += treasure->weight;
if (!bag->header){
bag->header = bag->tailer = treasure;
treasure->prev = treasure->next = NULL;
return;
}
//printf("\n1 ");
Treasure *p = bag->header;
for (; p; p = p->next){
if (treasure->weight <= p->weight){
treasure->next = p;
treasure->prev = p->prev;
if (p->prev) p->prev->next = treasure;
else bag->header = treasure;
p->prev = treasure;
break;
}
}
if (!p){
p = bag->tailer;
treasure->prev = p;
treasure->next = NULL;
p->next = treasure;
bag->tailer = treasure;
}
}
下面是3个测试:1000的随机数每次结果都不一样
input num of treasures:7
input capacity of bag:10
随机宝箱重量(y/n default to 'y'):n
input weight of treasures(<= capacity of bag):5 4 3 2 2 2 2
2 2 2 2 3 4 5
1 *** [10]:
2
2
2
4
2 *** [10]:
2
3
5
press 'q' to quit, others to continue:
input num of treasures:10
input capacity of bag:10
随机宝箱重量(y/n default to 'y'):n
input weight of treasures(<= capacity of bag):2 2 2 2 2 7 7 7 7 7
2 2 2 2 2 7 7 7 7 7
1 *** [9]:
2
7
2 *** [9]:
2
7
3 *** [9]:
2
7
4 *** [9]:
2
7
5 *** [9]:
2
7
press 'q' to quit, others to continue:
input num of treasures:1000
input capacity of bag:1000
随机宝箱重量(y/n default to 'y'):
(省略部分)
502 *** [994]:325 334 335
503 *** [926]:299 302 325
504 *** [888]:293 297 298
505 *** [877]:292 292 293
press 'q' to quit, others to continue:
漏了一行代码> <
================………
这个算法有问题,我设想是,对m个包裹,通过交换包裹的宝物,使第一个包裹中的剩余容量最大,但是失败了,不能按上面代码那样交换。
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本帖最后由 rolimi 于 2015-6-15 02:54 编辑 ]