13307130498_Li Huiying_Assignment12

13307130498/assignment12/Arctic Network.cpp

@@ -0,0 +1,53 @@
+#include<iostream>
+#include<cstdio>
+#include<algorithm>
+#include<cmath>
+using namespace std;
+int D[505][2],f[505];
+int i,j,k,n,s,p;
+struct A{
+    int x,y;
+    double w;
+}L[250010];
+bool fin(A x,A y){
+    return x.w<=y.w;
+}
+int find(int m){
+    if(m==f[m])return m;
+    return f[m]=find(f[m]);
+}
+void kru(){
+    int done;
+    double cnt[p];
+    for(i=done=0;i<k;i++){
+        int fx=find(L[i].x),fy=find(L[i].y);
+        if(fx!=fy){
+            f[fx]=fy;
+            cnt[done]=L[i].w;
+            done++;
+        }
+        if(done==p-1)break;
+    }
+    printf("%.2f\n",cnt[done-s]);
+}
+int main(){
+    scanf("%d",&n);
+    for(;n>0;n--){
+        scanf("%d%d",&s,&p);
+        for(i=0;i<p;i++){
+            scanf("%d%d",&D[i][0],&D[i][1]);
+            f[i]=i;
+        }
+        for(i=k=0;i<p;i++){
+            for(j=0;j<i;j++){
+                L[k].x=i;
+                L[k].y=j;
+                L[k].w = sqrt((D[i][0]-D[j][0])*(D[i][0]-D[j][0])+(D[i][1]-D[j][1])*(D[i][1]-D[j][1]));
+                k++;
+            }
+        }
+        sort(L,L+k,fin);
+        kru();
+    }
+    return 0;
+}

13307130498/assignment12/Flowery Trails.cpp

@@ -0,0 +1,88 @@
+#include<iostream>
+#include<cstdio>
+#include<vector>
+#include<stack>
+#include<cstring>
+using namespace std;
+int i,p,t;
+struct A{
+    int x,y,w;
+}L[250010];
+struct B{
+    int y,w;
+    B(int a,int b){y=a;w=b;}
+};
+vector<B> pre[10010];
+int Dist[10010],used[10010];
+long long result = 0;
+void dfs(int now){//cout<<"^_^"<<endl;
+    if(now==0||used[now]==1)return;
+    used[now]=1;
+    for(int j=0;j<pre[now].size();j++){
+        result += pre[now][j].w;
+        dfs(pre[now][j].y);
+    }
+}
+int main(){
+    cin>>p>>t;
+    for(Dist[0]=0,i=1;i<p;i++){
+        Dist[i]=-1;
+        used[i]=0;
+    }
+    for(i=0;i<t;i++)
+        scanf("%d%d%d",&L[i].x,&L[i].y,&L[i].w);
+    stack< pair<int,int> > s;
+    s.push(pair<int,int>(0,0));
+    int now,ed;
+    while(s.empty()==0){
+        now=s.top().first;
+        ed=s.top().second;
+        s.pop();
+        if(ed!=Dist[now])continue;
+        for(i=0;i<t;i++){
+            if(L[i].x==now){
+                if(Dist[L[i].y]==-1){
+                    Dist[L[i].y]=Dist[now]+L[i].w;
+                    pre[L[i].y].clear();
+                    pre[L[i].y].push_back(B(L[i].x,L[i].w));
+                    s.push(pair<int ,int>(L[i].y,Dist[now]+L[i].w));
+                }
+                else{
+                    if(Dist[L[i].y]>Dist[now]+L[i].w){
+                        pre[L[i].y].clear();
+                        Dist[L[i].y]=Dist[now]+L[i].w;
+                        pre[L[i].y].push_back(B(L[i].x,L[i].w));
+                        s.push(pair<int ,int>(L[i].y,Dist[now]+L[i].w));
+                    }
+                    else if(Dist[L[i].y]==Dist[now]+L[i].w){
+                        pre[L[i].y].push_back(B(L[i].x,L[i].w));
+                    }
+                }
+            }
+            else if(L[i].y==now){
+                if(Dist[L[i].x]==-1){
+                    Dist[L[i].x]=Dist[now]+L[i].w;
+                    pre[L[i].x].clear();
+                    pre[L[i].x].push_back(B(L[i].y,L[i].w));
+                    s.push(pair<int ,int>(L[i].x,Dist[now]+L[i].w));
+                }
+                else{
+                    if(Dist[L[i].x]>Dist[now]+L[i].w){
+                        pre[L[i].x].clear();
+                        Dist[L[i].x]=Dist[now]+L[i].w;
+                        pre[L[i].x].push_back(B(L[i].y,L[i].w));
+                        s.push(pair<int ,int>(L[i].x,Dist[now]+L[i].w));
+                    }
+                    else if(Dist[L[i].x]==Dist[now]+L[i].w){
+                        pre[L[i].x].push_back(B(L[i].y,L[i].w));
+                    }
+                }
+            }
+        }
+    }
+    now = p - 1;
+    dfs(now);
+    result*=2;
+    cout<<result<<endl;
+    return 0;
+}

13307130498/assignment12/食物链.cpp

@@ -0,0 +1,45 @@
+#include<iostream>
+#include<cstdio>
+using namespace std;
+int n,k,cnt;
+int f[50005],ran[50005];
+void inti(){
+    for(int i=1;i<=n;i++){
+        f[i]=i;
+        ran[i]=0;
+    }
+}
+int find(int m){
+    if(f[m]==m)return m;
+    int of = f[m];
+    f[m] = find(f[m]);
+    ran[m]=(ran[m]+ran[of])%3;
+    return f[m];
+}
+void uni(int d,int x,int y){
+    int fx=find(x),fy=find(y);
+    if(fx==fy)return;
+    f[fx]=fy;
+    ran[fx]=(ran[y]+d-1-ran[x]+3)%3;
+}
+bool jud(int d,int x,int y){
+    if(x>n||y>n||((x==y)&&(d==2)))return 0;
+    int fx=find(x),fy=find(y);
+    if(fx!=fy)return 1;
+    if(ran[x]==(ran[y]+d-1)%3)return 1;
+    else return 0;
+}
+int main(void){
+    cin>>n>>k;
+    int x,y,d;
+    inti();
+    for(cnt=0;k>0;k--){
+        scanf("%d%d%d",&d,&x,&y);
+        if(jud(d,x,y)==0)
+            cnt++;
+        else
+            uni(d,x,y);
+    }
+    cout<<cnt<<endl;
+    return 0;
+}