You may use C++ bitset. It requires O(Max / 8) bytes for space. If the array is sorted, there is O(n) solution with O(1) space complexity: keep two pointers, left = 0 and right = n - 1; while (l < r) { int diff = A[l] + A[r] - m; if (diff > 0) --r; else if (A[l] + A[r] < 0) ++l; else break; // found solution }
// check pointers if (l != r) then you found solution, so A[l] + A[r] == m On 22 окт, 15:32, RIDER <mohit...@gmail.com> wrote: > you have an array of n integers, how would you find the integer pairs > which sum to m? complexity? > > if we use hash table then should we implement efficient hash table in c > ++? -- You received this message because you are subscribed to the Google Groups "Algorithm Geeks" group. To post to this group, send email to algoge...@googlegroups.com. To unsubscribe from this group, send email to algogeeks+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/algogeeks?hl=en.