HDU_1863

// duti yiding yao feichang zixi !!!!//zhe ti wo fan de cuo wu jiu shi "buneng dandu de yi dian shifou chuxian lai panduan shifou liantong  "#include<iostream>#include<cstring>#include<cstdio>#include<algorithm>using namespace std;//  1-M ge cun zhuang//  M < 100//  while N = 0   end//  first line   N   M//  next  N line   num1  num2   price//  jin tian shi gan en jie , wo de shu ru fa huai diao le, zhen shi ri le gou !const int MAXN = 100+5;int pre[MAXN]; // zuxian jie dianint ans;//da anint sum;int u[MAXN];  //  di yi ge cun zhuangint v[MAXN];  //  di er ge cun zhuangint w[MAXN];  //  weight   quan  de  zhi void init(){memset(u, 0, sizeof(u));memset(v, 0, sizeof(v));memset(w, 0, sizeof(w));memset(pre, 0, sizeof(pre));}int cmp (const int i, const int j )  {return w[i] < w[j];   //  anzhao  price[] zhong yuansu  duiying de quanzhi lai jinxing cong xiao dao da de pai xu}int unionsearch(int root) // find   // root jie dian zai gang chuan ru de shi hou hai bu shi gen jie dian{int son = root;int temp;while(root != pre[root]){   //zhao dao le root jie dianroot = pre[root];}//lu jing ya suo!while(son!= root){temp = pre[son];pre[son] = root;son = temp;}return root;  }void join(int x, int y, int w) {  // w shi quan  int root1 = unionsearch(x);int root2 = unionsearch(y);if(root1 != root2){sum++;//WA dian::不能单纯地以所有点是否出现来判断是否能连通！要看点与点之间是否连通！  pre[root1] = root2;ans += w;}}//he bing int main(){int N, M;while(scanf("%d%d",&N,&M)&&N)  //dang N wei 0 shi  , ye yao quan bu shuru jieshu  caineng tuichu xunhuan{init();for(int i = 0; i < N; i++) {scanf("%d%d%d", &u[i], &v[i], &w[i]);pre[u[i]] = u[i]; //  gangkaishi mei ge cun zhuang de fujiedian dou shi zijipre[v[i]] = v[i];}//  dang cunzhuang zhijian de lu meiyou ba suoyou cunzhuang dou lian zai yiqi shi, buneng dai biao M>Nif(M == 1) {cout << 0 << endl;  // zhe li yinggai  shi 0 a !!continue;}// xian zai xu yao yige shuzu  lai cun fang  zhe xie price  xong xiao dao da de shun xuint price[MAXN];for(int i = 0; i < N; i++){price[i] = i;}// dui bian jinxing paixusort(price, price+N, cmp);ans = 0; //  zhe ge shi haofeisum = 1; // yijing liantong de dianfor(int i = 0; i < N; i++){//genju price yuansu de shunvu tian jia daolu // u[price[i]]  v[price[i]]   w[price[i]]join(u[price[i]], v[price[i]], w[price[i]]);}if(sum!=M) cout << "?" << endl;else cout << ans << endl;}return 0;}