fix

src/Quality.ts

@@ -20,7 +20,7 @@ export class Quality {
     assert(0 <= this.reliability && this.reliability <= 1);
     assert(this.cost >= 0);
     if (this.reliability === 0) {
-      return Infinity;
+      return 10000 + this.cost;
     } else {
       // 公式
       return this.delay + (1 - this.reliability) * 6 + this.cost * 0.1;