OJ-Problems-Source/HDOJ/5483_autoAC.cpp

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#include<stdio.h>
#include<string.h>
#include<algorithm>
#include<vector>
using namespace std;
#define scan(x) scanf("%d",&(x))
#define scan2(x,y) scanf("%d%d",&(x),&(y))
#define scan3(x,y,z) scanf("%d%d%d",&(x),&(y),&(z))
#define scan4(x,y,z,k) scanf("%d%d%d%d",&(x),&(y),&(z),&(k))
const int maxn = 3003;
const int maxm = maxn * maxn;
const int inf = 1000000000;
int n, m;
__int64 mst;
int map[maxn][maxn];
int dp[maxn][maxn], best[maxn][maxn];
int dis[maxn], pre[maxn];
bool vis[maxn];
vector<int> edge[maxn];
#include<iostream>
int minz(int a, int b)
{
return a < b ? a : b;
}
void init()
{
int i, j;
for(i = 0; i < n; i++)
{
for(j = 0; j < n; j++)
map[i][j] = dp[i][j] = inf;
edge[i].clear();
vis[i] = 0;
pre[i] = -1;
dis[i] = inf;
}
}
void input()
{
for(int i=0;i<n;i++){
for(int j=i+1;j<n;j++){
int w;scan(w);
map[i][j] = map[j][i] = w;
}
}
}
void prim()
{
int i, j, k;
for(i = 1; i < n; i++)
{
dis[i] = map[0][i];
pre[i] = 0;
}
dis[0] = inf;
vis[0] = 1;
pre[0] = -1;
mst = 0;
for(i = 0; i < n-1; i++)
{
k = 0;
for(j = 1; j < n; j++)
if(!vis[j] && dis[k] > dis[j])
k = j;
vis[k] = 1;
mst += dis[k];
if(pre[k] != -1)
edge[k].push_back(pre[k]),
edge[pre[k]].push_back(k);
for(j = 1; j < n; j++)
if(!vis[j] && dis[j] > map[k][j] )
dis[j] = map[k][j], pre[j] = k;
}
}
int dfs1(int u, int fa, int rt)
{
int i;
for(i = 0; i < edge[u].size(); i++)
{
int v = edge[u][i];
if(v == fa) continue;
dp[rt][u] = minz(dp[rt][u], dfs1(v, u, rt));
}
if(fa != rt) dp[rt][u] = minz(dp[rt][u], map[rt][u]);
return dp[rt][u];
}
int dfs2(int u, int fa, int rt)
{
int i;
int ans = dp[u][rt];
for(i = 0; i < edge[u].size(); i++)
{
int v = edge[u][i];
if(v == fa) continue;
ans = minz(ans, dfs2(v, u, rt));
}
return ans;
}
void solve()
{
int i,j;
for(i = 0; i < n; i++)
dfs1(i, -1, i);
for(i = 0; i < n; i++)
for(j = 0; j < edge[i].size(); j++)
{
int v = edge[i][j];
best[i][v] = best[v][i] = dfs2(v, i, i);
}
}
void query()
{
int ans =0 ;
for(int i=0;i<n;i++){
int x=i;
for(int j=0;j<edge[i].size() ; j++){
int y=edge[i][j];
if(x<y) continue;
int sum = mst - map[x][y] + best[x][y];
if(sum != mst){
ans++;
}
}
}
printf("%d\n",ans);
}
int main(){
int T;scan(T);
while(T--){
scan(n);
m=n-1;
init();
input();
prim();
solve();
query();
}
}