kuangbin专题专题四 MPI Maelstrom POJ - 1502

题目链接：https://vjudge.net/problem/POJ-1502

dijkstra板子题，题目提供下三角情况，不包含正对角线，因为有题意都为0，处理好输入，就是一个很水的题。

---

 #include <iostream>
 #include <cstring>
 #include <algorithm>
 #include <cstdio>
 #include <string>
 #include <vector>
 using namespace std;

 typedef long long LL;
 #define inf (1LL << 30) - 1
 #define rep(i,j,k) for(int i = (j); i <= (k); i++)
 #define rep__(i,j,k) for(int i = (j); i < (k); i++)
 #define per(i,j,k) for(int i = (j); i >= (k); i--)
 #define per__(i,j,k) for(int i = (j); i > (k); i--)

 const int N = ;
 vector<pair<int,int> > G[N];
 int val[N];
 int vis[N];
 int n;

 int fun(string& x){
     int sum = ;

     rep__(i,,(int)x.length()) sum = sum *  + (x[i] - '');

     return sum;
 }

 void input(){

     string w;
     rep(i,,n){
         rep__(j,,i){
             cin >> w;

             if(w[] == 'x') continue;
             int W = fun(w);
             G[i].push_back(make_pair(j,W));
             G[j].push_back(make_pair(i,W));
         }
     }
 }

 int dijkstra(){

     if(n == ) return ;
     val[] = ;
     rep(i,,n) val[i] = inf;

     rep__(i,,(int)G[].size()) val[G[][i].first] = G[][i].second;
     vis[] = true;

     rep(i,,n){

         int x = -;
         int v = inf;

         rep(j,,n){
             if(!vis[j] && v > val[j]) v = val[x = j];
         }

         if(x == -) continue;
         vis[x] = true;

         rep__(o,,(int)G[x].size()){
             int v = G[x][o].first;
             int w = G[x][o].second;
             if(!vis[v] && val[v] > val[x] + w)
                 val[v] = val[x] + w;
         }
     }

     int ans = ;
     rep(i,,n) ans = max(ans, val[i]);

     return ans;
 }

 int main(){

     ios::sync_with_stdio(false);
     cin.tie();

     cin >> n;
     input();
     cout << dijkstra() << endl;

     getchar();getchar();
     return ;
 }