来自一道oj作业题:
具体解决方案参考了以下两份资料:
关于最大曼哈顿距离的讲解
曼哈顿距离的维护
非常感谢两位作者。
我的代码如下(维护方式采用了两个优先队列数组):
#pragma warning(disable:4996)
#include <cstring>
#include <cstdio>
#include <algorithm>
#include <queue>
using namespace std;
int a[6];
bool vis[60005];
typedef struct ascending_node
{
int id, data;
bool operator<(const ascending_node& a) const
{
return data > a.data;
}
}anode;
typedef struct descending_node
{
int id, data;
bool operator<(const descending_node& a) const
{
return data < a.data;
}
}dnode;
int main()
{
int m, n, sum=0;
int result = 0;
int in[6];
scanf("%d %d", &m, &n);
priority_queue<anode> apq[1 << 5];
priority_queue<dnode> dpq[1 << 5];
anode t1;
dnode t2;
memset(vis, false, sizeof(vis));
int insert, dele;
for (int i = 0; i < m; i++) {
scanf("%d", &insert);
if (!insert) {
t1.id = i;
t2.id = i;
for (int k = 0; k < n; k++) {
scanf("%d", &in[k]);
}
for (int j = 0; j < 1 << n; j++) {
for (int k = 0; k < n; k++) {
int r = j & 1 << k; //1为+,0为-,&符号表示当两二进制数同样位置上均为1时结果的该位置为1
if (r) sum += in[k];
else sum -= in[k];
}
t1.data = sum;
apq[j].push(t1);
t2.data = sum;
dpq[j].push(t2);
sum = 0;
}
}
else {
scanf("%d", &dele);
vis[dele-1] = 1;
}
for (int q = 0; q < 1<<n; q++) {
int temp;
while (vis[apq[q].top().id] == 1) {
apq[q].pop();
}
while (vis[dpq[q].top().id] == 1) {
dpq[q].pop();
}
temp = dpq[q].top().data - apq[q].top().data;
if (temp > result) {
result = temp;
}
}
printf("%d\n", result);
result = 0;
}
}