commit 27e6f7ca19c33ffd31a8a810a6114374fe6eb6b4
Author: Lrixin <2565381053@qq.com>
Date:   Thu Aug 6 16:15:39 2020 +0800

    wrote a cpp file

diff --git a/Hello.cpp b/Hello.cpp
new file mode 100644
index 0000000..c67181e
--- /dev/null
+++ b/Hello.cpp
@@ -0,0 +1,99 @@
+#include<iostream>
+#include<algorithm>
+#include<cstring>
+#include<cmath>
+#include<cstdio>
+using namespace std;
+
+const int INF = 1e9;
+const int maxn = 2e2 + 5;
+
+struct edge{
+    int u, v, w;
+    edge() :u(),v(),w(){}
+    edge(int a,int b,int c) :u(a),v(b),w(c){}
+    bool operator<(const edge& op) const{
+        return w < op.w;
+    }
+} e[maxn*maxn];
+
+int f[maxn], sum = 0;
+int used[maxn*maxn];
+void add_edge(int u,int v,int w){
+    e[sum]=edge(u,v,w);
+    sum++;
+}
+
+int findroot(int x){
+    return (f[x] == x )? x : (f[x]= findroot(f[x]));
+}
+
+void init(int n){
+    for (int i = 0; i <= n;i++){
+        f[i] = i;
+    }
+    sum = 0;
+    memset(used, 0, sizeof(used));
+}
+
+int kruskal(int n,int m,int op){
+    for (int i = 0; i <= n;i++){
+        f[i] = i;
+    }
+    int ans=0,cnt=0;
+    for (int i = 0; i < m;i++){
+        if(i==op){
+            continue;
+        }
+        int fx=findroot(e[i].u);
+        int fy = findroot(e[i].v);
+        if(fx!=fy){
+            f[fy] = fx;
+            ans += e[i].w;
+            cnt++;
+            if(op==-1){
+                used[cnt - 1] = i;
+            }
+            if(cnt==n-1){
+                return ans;
+            }
+        }
+    }
+    return (cnt < n - 1) ? INF : (ans);
+}
+
+int main(){
+    int t;
+    cin >> t;
+    int cas = 1;
+    while (t--)
+    {
+        int n, m;
+        cin>>n>>m;
+        init(n);
+        int u, v, w;
+        int tt = m;
+        while (tt--)
+        {
+            cin >> u >> v >> w;
+            add_edge(u, v, w);
+        }
+        sort(e, e + m);
+        int mst = kruskal(n,m,-1);
+        int smst = INF;
+        for (int i = 0; i < m;i++){
+            smst = min(smst, kruskal(n, m, used[i]));
+        }
+        printf("Case #%d : ", cas++);
+        if(mst==INF){
+            printf("No way\n");
+        }
+        else if(smst==INF){
+            printf("No second way\n");
+        }
+        else{
+            printf("%d\n", smst);
+        }
+    }
+    return 0;
+}
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