Create 1498. Number of Subsequences That Satisfy the Given Sum Condition

Author: rajatag03

1498. Number of Subsequences That Satisfy the Given Sum Condition

@@ -0,0 +1,65 @@
+class Solution {
+    public int numSubseq(int[] nums, int target) {
+        Arrays.sort(nums);
+        int mod = 1_000_000_007;
+        int result =0;
+        int n = nums.length;
+        int[] power = new int[n];
+        power[0] = 1;
+        for(int i=1;i<n;i++){
+            power[i] = (power[i-1] * 2) % mod;
+        }
+
+        for(int left=0;left<n;left++){
+            int right = binarySearch(nums,target- nums[left]) - 1;
+            if(right>=left){
+                result += power[right - left];
+                result %= mod;
+            }
+        }
+
+        return result;
+    }
+
+    private int binarySearch(int[] nums, int value){
+        int low = 0, high = nums.length - 1;
+        while(low<=high){
+            int mid = low + (high - low)/2;
+            if(nums[mid]<=value){
+                low = mid + 1;
+            }
+            else{
+                high = mid - 1;
+            }
+        }
+        return low;
+    }
+}
+
+class Solution {
+    public int numSubseq(int[] nums, int target) {
+        Arrays.sort(nums);
+        int mod = 1_000_000_007;
+        int result =0;
+        int n = nums.length;
+        int[] power = new int[n];
+        power[0] = 1;
+        for(int i=1;i<n;i++){
+            power[i] = (power[i-1] * 2) % mod;
+        }
+        int left = 0 , right = n - 1;
+
+        while(left<=right){
+            if(nums[left] + nums[right] <= target){
+                result += power[right - left];
+                result %= mod;
+                left++;
+            }
+            else{
+                right--;
+            }
+        }
+
+        return result;
+    }
+}