add README.md

README.md

@@ -2,13 +2,13 @@
 ```
 cd nszw-solver
 make
-./solve QUESTIONFILE
+./solve < QUESTIONFILE
 ```
 or 
 ```
 cd nszw-solver
 g++ -o solve solver.cpp main.cpp io.c router/router.cpp -std=c++11
-./a.out QUESTIONFILE
+./solve < QUESTIONFILE
 ```
 
 # 必要ヘッダ