Create 5870_fzmh.cpp

From http://www.cnblogs.com/fzmh/p/5861485.html

HDOJ/5870_fzmh.cpp

@@ -0,0 +1,152 @@
+#include<cstdio>
+#include<vector>
+#include<set>
+#include<queue>
+#include<algorithm>
+#define mp make_pair
+#define pb push_back
+#define fi first
+#define sc second
+using namespace std;
+const int N = 201010;
+const int M = 2010101;
+const int inf = 2100000000;
+typedef pair<int,int> P; 
+priority_queue<P,vector<P>,greater<P> > Q;
+int n,m,i,a,b,c,dis[N],cnt[N],dis1[N],cnt1[N],dis2[N],cnt2[N],X;
+int id[N],ID[N],Id[N];
+vector<P> e[N];
+void gao(int x)
+{
+    int i;
+    for (i=1;i<=n;i++)
+    dis[i]=inf,cnt[i]=0;
+    dis[x]=0;
+    cnt[x]=1;
+    Q.push(mp(0,x));
+    while (!Q.empty())
+    {
+        P tmp=Q.top();
+        Q.pop();
+        x=tmp.sc;
+        if (dis[x]!=tmp.fi) continue;
+        for (i=0;i<e[x].size();i++)
+        if (dis[x]+e[x][i].sc<dis[e[x][i].fi])
+        {
+            dis[e[x][i].fi]=dis[x]+e[x][i].sc;
+            cnt[e[x][i].fi]=cnt[x];
+            Q.push(mp(dis[e[x][i].fi],e[x][i].fi));
+        }
+        else
+        if (dis[x]+e[x][i].sc==dis[e[x][i].fi])
+        {
+            cnt[e[x][i].fi]+=cnt[x];
+            if (cnt[e[x][i].fi]>X) cnt[e[x][i].fi]=X;
+        }
+    }
+}
+
+int ls[M],rs[M],s[M],tot,root[N];
+void build(int &x,int a,int b)
+{
+    x=++tot;
+    ls[x]=rs[x]=s[x]=0;
+    if (b-a>1)
+    {
+        int m=(a+b)>>1;
+        build(ls[x],a,m);
+        build(rs[x],m,b);
+    }
+}
+void insert(int y,int &x,int a,int b,int l,int r)
+{
+    x=++tot;
+    ls[x]=ls[y];rs[x]=rs[y];s[x]=s[y]+1;
+    if ((a<=l)&&(r<=b))
+    return;
+    int m=(l+r)>>1;
+    if (a<m) insert(ls[y],ls[x],a,b,l,m);
+    if (m<b) insert(rs[y],rs[x],a,b,m,r);
+}
+int query(int x,int a,int b,int l,int r)
+{
+    if ((a<=l)&&(r<=b))
+    return s[x];
+    int m=(l+r)>>1,ans=0;
+    if (a<m) ans+=query(ls[x],a,b,l,m);
+    if (m<b) ans+=query(rs[x],a,b,m,r);
+    return ans;
+}
+bool cmp(int a,int b)
+{
+    return dis2[a]<dis2[b];
+}
+bool CMP(int a,int b)
+{
+    return cnt2[a]>cnt2[b];
+}
+int main()
+{
+    while (~scanf("%d%d",&n,&m))
+    {
+    if (n+m==0) return 0;
+    for (i=1;i<=n;i++) e[i].clear();
+    scanf("%d",&X);
+    for (i=1;i<=m;i++)
+    {
+        scanf("%d%d%d",&a,&b,&c);
+        e[a].pb(mp(b,c));
+        e[b].pb(mp(a,c));
+    }
+    gao(1);
+    for (i=1;i<=n;i++)
+    dis1[i]=dis[i],cnt1[i]=cnt[i];
+    gao(n);
+    for (i=1;i<=n;i++)
+    dis2[i]=dis[i],cnt2[i]=cnt[i];
+    
+    tot=0;
+    build(root[0],0,n);
+    for (i=1;i<=n;i++)
+    id[i]=i;
+    sort(id+1,id+1+n,cmp);
+    for (i=1;i<=n;i++)
+    ID[id[i]]=i;
+    
+    for (i=1;i<=n;i++)
+    Id[i]=i;
+    sort(Id+1,Id+1+n,CMP);
+    for (i=1;i<=n;i++)
+        insert(root[i-1],root[i],ID[Id[i]]-1,ID[Id[i]],0,n);
+    long long ans=0;
+    for (i=1;i<=n;i++)
+    {
+        int l=1,r=n;
+        while (l<=r)
+        {
+            m=(l+r)>>1;
+            if (dis2[id[m]]+dis1[i]+1<=dis1[n]) l=m+1;else r=m-1;
+        }
+        int j=r;
+
+        l=1;r=n;
+        while (l<=r)
+        {
+            m=(l+r)>>1;
+            if (1LL*cnt1[i]*cnt2[Id[m]]>=X) l=m+1;else r=m-1;
+        }
+        
+        if (j) ans=ans+query(root[r],0,j,0,n);
+        
+        
+        for (int k=0;k<e[i].size();k++)
+        if (dis2[e[i][k].fi]+1+dis1[i]<=dis1[n])
+        if (1LL*cnt1[i]*cnt2[e[i][k].fi]>=X) ans--;
+    
+        if (dis1[i]+dis2[i]+1<=dis1[N])
+        if (1LL*cnt1[i]*cnt2[i]>=X) ans--;
+        
+    }
+    printf("%lld\n",ans);
+    }
+}