分析:考虑到是个完全图,应该使用prim算法,因为prim是按照点来的,不过还是喜欢krusal,试一下看看能不能过。。
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很遗憾超时了,我再试一下不更新到底会怎么样,不更新到底能过。。不过也用了700多ms
#include<iostream>
#include<algorithm>
#include<stdio.h>
#include<math.h>
#include<string.h>
#include<queue>
#include<stack>
using namespace std;
const int maxn = 2005;
int f[maxn];
char p[maxn][10];
struct node
{
int u, v, len;
friend bool operator < (node a, node b)
{
return a.len > b.len;
}
};
int Len(char a[], char b[])
{
int sum = 0;
for(int i=0; a[i]; i++)
if(a[i] != b[i])sum++;
return sum;
}
int Find(int x)
{
if(f[x] != x)
f[x] = Find(f[x]);
return f[x];
}
int main()
{
int N;
while(scanf("%d", &N) != EOF && N)
{
node s;
priority_queue<node> Q;
for(s.u=1; s.u<=N; s.u++)
{
f[s.u] = s.u;
scanf("%s", p[s.u]);
for(s.v=1; s.v<s.u; s.v++)
{
s.len = Len(p[s.u], p[s.v]);
Q.push(s);
}
}
int ans = 0, t=0;//如果已经链接了N-1条边就可以结束了
while(Q.size() && t < N-1)
{
s = Q.top();Q.pop();
int u = Find(s.u), v = Find(s.v);
if(u != v)
{
t++;
f[v] = u;
ans += s.len;
}
}
printf("The highest possible quality is 1/%d. ", ans);
}
return 0;
#include<algorithm>
#include<stdio.h>
#include<math.h>
#include<string.h>
#include<queue>
#include<stack>
using namespace std;
const int maxn = 2005;
int f[maxn];
char p[maxn][10];
struct node
{
int u, v, len;
friend bool operator < (node a, node b)
{
return a.len > b.len;
}
};
int Len(char a[], char b[])
{
int sum = 0;
for(int i=0; a[i]; i++)
if(a[i] != b[i])sum++;
return sum;
}
int Find(int x)
{
if(f[x] != x)
f[x] = Find(f[x]);
return f[x];
}
int main()
{
int N;
while(scanf("%d", &N) != EOF && N)
{
node s;
priority_queue<node> Q;
for(s.u=1; s.u<=N; s.u++)
{
f[s.u] = s.u;
scanf("%s", p[s.u]);
for(s.v=1; s.v<s.u; s.v++)
{
s.len = Len(p[s.u], p[s.v]);
Q.push(s);
}
}
int ans = 0, t=0;//如果已经链接了N-1条边就可以结束了
while(Q.size() && t < N-1)
{
s = Q.top();Q.pop();
int u = Find(s.u), v = Find(s.v);
if(u != v)
{
t++;
f[v] = u;
ans += s.len;
}
}
printf("The highest possible quality is 1/%d. ", ans);
}
return 0;
}