3528. 单位转换 I

题意

题目链接

思路

dfs

代码

class Solution {
public:
    vector<int> baseUnitConversions(vector<vector<int>>& conversions) {
        vector<int> ans(conversions.size() + 1, 0);
        ans[0] = 1;
        map<int, map<int, int>> visit;
        for (auto &index : conversions) {
            visit[index[0]][index[1]] = index[2];
        }
        const long mod = 1000000000 + 7;
        queue<int> Q;
        Q.push(0);
        while (!Q.empty()){
            auto &index = Q.front();
           // cout << ans.size() << endl;
            for (auto &it : visit[index]) {
             //   cout << it.first <<" " << index <<" "<< it.second << endl;
                ans[it.first] = (ans[index] % mod)* (it.second % mod) % mod; 
                Q.push(it.first);
            }
            Q.pop();
        }
        return ans;
    }
};