1498

class Solution {
public:
    int numSubseq(vector<int>& nums, int target) {
        sort(nums.begin(), nums.end());
        int ans=0;
        int pow[nums.size()], mod=int(1e9)+7;
        pow[0] = 1;
        for(int i=1; i<nums.size(); i++)
            pow[i] = (pow[i-1]*2LL)%mod;

        int left=0, right=nums.size()-1;
        while(left <= right){
            if(nums[left] + nums[right] > target)
                right--;
            else
                ans = (ans+pow[right-left++])%mod;
        }
        return ans;
    }
};