| # | Title | Solutions | Video | Difficulty | Tag

|-----|----------------|---------------|--------|-------------|-------------

|1711|[Count Good Meals](https://leetcode.com/problems/count-good-meals/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1711.java)||Medium|Array, HashTable, Two Pointers|

|1710|[Maximum Units on a Truck](https://leetcode.com/problems/maximum-units-on-a-truck/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1710.java)||Easy|Greedy, Sort|

|1708|[Largest Subarray Length K](https://leetcode.com/problems/largest-subarray-length-k/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1708.java)||Easy|Array, Greedy|

|1704|[Determine if String Halves Are Alike](https://leetcode.com/problems/determine-if-string-halves-are-alike/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1704.java)||Easy|String|

packagecom.fishercoder.solutions;

importjava.util.HashMap;

importjava.util.Map;

publicclass_1711 {

publicstaticclassSolution1 {

privatestaticfinallongMODUALR =1000000007;

publicintcountPairs(int[]deliciousness) {

Map<Integer,Integer>map =newHashMap<>();

longpairs =0;

for (inti =0;i <deliciousness.length;i++) {

intpower =1;

for (intj =0;j <22;j++) {//we only need to go up to 21 since one of the constraints is: 0 <= deliciousness[i] <= 2 to the power of 20

if (map.containsKey(power -deliciousness[i])) {

pairs +=map.get(power -deliciousness[i]);

pairs %=MODUALR;

}

power *=2;

}

map.put(deliciousness[i],map.getOrDefault(deliciousness[i],0) +1);

}

return (int)pairs;

}

}

}

packagecom.fishercoder;

importcom.fishercoder.solutions._1711;

importorg.junit.BeforeClass;

importorg.junit.Test;

importstaticorg.junit.Assert.assertEquals;

publicclass_1711Test {

privatestatic_1711.Solution1solution1;

privatestaticint[]deliciousness;

publicstaticvoidsetup() {

solution1 =new_1711.Solution1();

}

publicvoidtest1() {

deliciousness =newint[]{1,3,5,7,9};

assertEquals(4,solution1.countPairs(deliciousness));

}

publicvoidtest2() {

deliciousness =newint[]{1,1,1,3,3,3,7};

assertEquals(15,solution1.countPairs(deliciousness));

}

publicvoidtest3() {

deliciousness =newint[]{64,64,64,64,64,64,64,64,64,64,64,64,64,64,64,64,64,64,64,64,64,64,64,64,64,64,64,64,64,64,64,64,64};

assertEquals(528,solution1.countPairs(deliciousness));

}

}