leetcode743

class Solution {
public:
    int networkDelayTime(vector<vector<int>>& times, int N, int K) {
        vector<vector<int> > graph(N + , vector<int>(N + , ));
        vector<int> cost(N + );
        vector<bool> visited(N + , false); 

        for (int i = ; i < times.size(); ++i) { graph[times[i][]][times[i][]] = times[i][]; }
        for (int i = ; i <= N; ++i) { cost[i] = graph[K][i]; }
        cost[K] = ;
        visited[K] = true;

        for (int i = ; i <= N; ++i) {
            int minNode = findMinNode(cost, visited);
            if (minNode == ) { break; }
            for (int j = ; j <= N; ++j) {
                if (!visited[j] && cost[j] > cost[minNode] + graph[minNode][j]) {
                    cost[j] = cost[minNode] + graph[minNode][j];
                }
            }
            visited[minNode] = true;
        }

        return calSum(cost);
    }

    int findMinNode(vector<int>& cost, vector<bool>& visited) {
        int minIndex = , minV = ;
        for (int i = ; i < cost.size(); ++i) {
            if (!visited[i] && minV > cost[i]) {
                minIndex = i;
                minV = cost[i];
            }
        }

        return minIndex;
    }

    int calSum(vector<int>& cost) {
        int sum = ;
        for (int i = ; i < cost.size(); ++i) {
            if (cost[i] == ) { return -; }
            if (sum < cost[i]) { sum = cost[i]; }
        }

        return sum;
    }
};