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GCD pairTime Limit: 16000/8000 MS (Java/Others) Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 467 Accepted Submission(s): 150 Problem Description The greatest common divisor (gcd) of two or more integers (at least one of which is not zero) is the largest positive integer that divides the numbers without a remainder. Now I will give you a simple problem about gcd again. Given a sequence of N integers, A = {a1, a2, ..., aN }. For every pair of < l, r >( 1 ¡Ü l ¡Ü r ¡Ü N ), defined a function F (l, r) = gcd(ai)( l ¡Ü i ¡Ü r ) that is the greatest common divisor of all the integers in the subsequence {al, al+1, ..., ar } Obviously, There are N * (N + 1)/2 pair of < l, r >( 1 ¡Ü l ¡Ü r ¡Ü N ). We can get the rank of pair < l, r > through the following code. 1 pair<int,int> get_RANK(int l,int r) 2 { 3 map<int,int>mp; 4 int k1 = 1, k2 = 1; 5 for(int i = 1;i <= N;i++) 6 for(int j = i;j <= N;j++) 7 { 8 if(i == l && j == r)continue; 9 if(F(i,j) < F(l,r)) 10 { 11 if(mp.find(F(i,j)) != mp.end())continue; 12 k1++; 13 mp[F(i,j)] = 1; 14 } 15 else if(F(i,j) == F(l,r)) 16 { 17 if(i < l || (i == l && j < r))k2++; 18 } 19 } 20 return make_pair(k1,k2); 21 } (If you don¡¯t know C++, what a sad story! Sorry!) There are Q queries, you need to answer the following two queries: ¡ñ SELECT k1 k2: ask for the pair < l, r > which is rank < k1, k2 >.If there is no such pair output -1. ¡ñ RANK l r: ask for the rank < k1, k2 > of the pair < l, r > Input The first line of the input is T (1 ¡Ü T ¡Ü 10), which stands for the number of test cases you need to solve. The first line of each case contains two integers N ,Q (1 ¡Ü N, Q ¡Ü105),denoting the number of integers and queries, respectively. The second line contains N integers, a1, a2, ..., aN (1 ¡Ü ai ¡Ü 105). For the next Q lines, contain instructions ¡°SELECT k1 k2¡± or ¡°RANK l r¡± (1 ¡Ü k1, k2 ¡Ü N * (N + 1)/2,1 ¡Ü l ¡Ü r ¡Ü N ), Output For each test case, print a line ¡°Case #t:¡±(without quotes, t means the index of the test case) at the beginning. For each query, output the answer. Sample Input
Sample Output
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