9494 */
9595public class FlatlandSpaceStations {
9696 public static int flatlandSpaceStations (int noOfCities , int [] spaceStations ){
97- int noSpaceStations = spaceStations .length ;
97+ int noOfSpaceStations = spaceStations .length ;
9898
99- if (noOfCities == noSpaceStations ) return 0 ;
99+ if (noOfCities == noOfSpaceStations ) return 0 ;
100100// if ( noOfCities == 1 && noSpaceStations == 1 ) return 0;
101- else if ( noOfCities == 2 && noSpaceStations == 1 ) return 1 ;
101+ else if ( noOfCities == 2 && noOfSpaceStations == 1 ) return 1 ;
102102// else if ( noOfCities == 2 && noSpaceStations == 2 ) return 0;
103- else if ( noOfCities == 3 && noSpaceStations == 2 ) return 1 ;
103+ else if ( noOfCities == 3 && noOfSpaceStations == 2 ) return 1 ;
104104
105105
106- if ( noSpaceStations == 1 ) {
106+ if ( noOfSpaceStations == 1 ) {
107107 int firstSpaceStation = spaceStations [0 ];
108108
109109 if ( noOfCities == 3 )
110110 return Math .max (firstSpaceStation , noOfCities -firstSpaceStation -1 );
111111
112- else if ( firstSpaceStation == noSpaceStations -1 || noSpaceStations == 3 )
112+ else if ( firstSpaceStation == noOfSpaceStations -1 || noOfSpaceStations == 3 )
113113 return Math .max (firstSpaceStation -1 , noOfCities -firstSpaceStation -1 );
114114
115115 else
@@ -122,18 +122,47 @@ else if ( firstSpaceStation == noSpaceStations-1 || noSpaceStations == 3 )
122122
123123 int maxDistance = 0 ;
124124 int i =0 ;
125- for (; i <noSpaceStations -1 ; i ++){
126- int distanceDiff = spaceStations [i +1 ]-spaceStations [i ];
127125
128- if ( maxDistance < distanceDiff )
129- maxDistance = distanceDiff ;
130- }
126+ // for(; i<noSpaceStations-1; i++) {
131127
132- if (spaceStations [i ] < noSpaceStations ) {
133- int distanceFromLast = noOfCities -1 -spaceStations [i ];
128+ //check if the space station are consecutive last
129+ // if (spaceStations[i] == noSpaceStations-2)
130+ //
131+ //
132+ // int distanceDiff = spaceStations[i+1]-spaceStations[i];
133+ //
134+ // if ( maxDistance < distanceDiff)
135+ // maxDistance = distanceDiff;
136+ // }
134137
135- if (maxDistance < distanceFromLast )
136- return distanceFromLast ;
138+ // if (spaceStations[i] < noSpaceStations) {
139+ // int distanceFromLast = noOfCities-1-spaceStations[i];
140+ //
141+ // if (maxDistance < distanceFromLast)
142+ // return distanceFromLast;
143+ // }
144+ 145+ // lets get the distance from the first city
146+ // to first space station
147+ int j =0 ;
148+ while ( j < noOfCities -1 ) {
149+ // if space station is ahead of city
150+ if ( spaceStations [i ] > j ) {
151+ maxDistance = spaceStations [i ] - j ;
152+ 153+ // suppose next city is next to space station
154+ // it should not be a consecutive space station
155+ // if it is, increment the index until next
156+ // city is found.
157+ j = spaceStations [i ]+1 ;
158+ for ( int k =j ; k < noOfSpaceStations -1 ; k ++ ){
159+ 160+ if ( k != spaceStations [k ]){
161+ j = k ;
162+ break ;
163+ }
164+ }
165+ } else j ++;
137166 }
138167
139168 return maxDistance ;
@@ -168,6 +197,18 @@ void hasFourCitiesTwoStationsAtThirdAndFourth() {
168197
169198 Assertions .assertEquals (expectedMaxDistance ,
170199 FlatlandSpaceStations .flatlandSpaceStations (noOfCities , spaceStaions ));
200+ 201+ /**
202+ * Assertion Fail.
203+ * Expected :2
204+ * Actual :1
205+ *
206+ * The logic to get the maximum distance fails.
207+ * As the stations are in the end, we have to
208+ * get the distance from the first city to that
209+ * station.
210+ *
211+ */
171212 }
172213
173214 @ Test
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