Data Abstraction and Problem Solving with C++ Walls and Mirrors by Frank M. Carrano
Text Home Text Errata	isPathStack.cpp Go to the documentation of this file. bool Map::isPath(int originCity, int destinationCity) { Stack aStack; int topCity, nextCity; bool success; unvisitAll(); // clear marks on all cities // push origin city onto aStack, mark it visited try { aStack.push(originCity); markVisited(originCity); aStack.getTop(topCity); while (!aStack.isEmpty() && (topCity != destinationCity)) { // Loop invariant: The stack contains a directed path // from the origin city at the bottom of the stack to // the city at the top of the stack // find an unvisited city adjacent to the city on the // top of the stack success = getNextCity(topCity, nextCity); if (!success) aStack.pop(); // no city found; backtrack else // visit city { aStack.push(nextCity); markVisited(nextCity); } // end if if(!aStack.isEmpty()) aStack.getTop(topCity); } // end while if (aStack.isEmpty()) return false; // no path exists else return true; // path exists } catch (StackException e) { cout << e.what() << endl; } // end try } // end isPath

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