direct graphs的用法和樣例：
例句
- And the coefficients of eigen-polynomial expressions were closely related to the circular sets of a directional graph.
而特征多項式的系數與有向圖的圓族有著(zhù)密切的關(guān)系。 - In a directed graph, the decision variables of the shortest path computation must be determined by a constraint that is called Kirchoff's constraint.
摘要已知一個(gè)有向圖，求解兩點(diǎn)間的最短路徑的決策變量滿(mǎn)足基爾霍夫約束關(guān)系。
