A题: bool judge(int x) { // write code here if(1<=x<9) return true; int res1=x%10,res2=0; while(x>=10) { x/=10; } res2=x; return res1==res2?true:false; } B题: int countTriplets(vector<int>& arr, int a, int b) { // write code here long long res=0; long long mod=100000...