1001 number pairs in array and equal to K

Base time limit: 1 seconds space limit: 131072 KB Score: 5 Difficulty: 1-level algorithm problem

Given an integer k and an unordered array, the elements of a,a are n distinct integers, finding the pairs of all and equal k in array a. For example k = 8, Array a:{-1,6,5,3,4,2,9,0,8}, all and equal to 8 pairs include ( -1,9), (0,8), (2,6), (3,5). Input

Line 1th: 2 numbers separated by a space, K n,n is the length of a array. (2 <= n <= 50000,-10^9 <= K <= 10^9) Section 2-n + 1 rows: N elements of a array. ( -10^9 <= a[i] <= 10^9)

Output

Line 1-m: 2 numbers per line, requires a smaller number in front, and the m number is in ascending order of smaller numbers. If there is no one set of solutions output: no solution.

Input example

8 9-165342908

Output example

-1 90 82 63 5

Tonight, the only one without a topic, because I and t change problem is also adjusted for a long time.

The AC code is attached:

1#include <iostream>2#include <algorithm>3#include <cstring>4 using namespacestd;5 6 Const intinf=1<< -;7 8 inta[50010];9 Ten intMain () { One     intNLong LongK; ACin>>k>>N; -      for(intI=0; i<n;i++){ -Cin>>A[i]; the     } -Sort (a,a+n); -     /*for (int i=0;i<n;i++) - cout<<a[i]<< "";*/ +     intt=n-1, i=0, ans=0; -      while(1){ +         if(a[i]+a[t]==k&&i<t) { Acout<<a[i]<<" "<<a[t]<<Endl; atans++; -i++; -         } -         Else if(a[i]+a[t]>k) { -t--; -         } in         Else if(a[i]+a[t]<k) { -i++; to         } +         if(i>=t) -          Break; the     } *     if(ans==0){ $cout<<"No Solution"<<Endl;Panax Notoginseng     } -     return 0; the}

Best of all:

1#include <stdio.h>2#include <algorithm>3 using namespacestd;4 5 Const intN =50005;6 7 intk, N;8 intA[n];9 Ten intMain () { One   intI, J; Ascanf"%d%d", &k, &n); -    for(i =0; I < n; i++) { -scanf"%d", &a[i]); the   } -Sort (A, A +n); -   BOOLFlag =false; -i =0; j = N-1; +    while(I <j) { -n = a[i] +A[j]; +     if(n = = k) {printf ("%d%d\n", a[i++], a[j--]); Flag =true; } A     Else if(N < k) {i++; } at     Else{j--; } -   } -   if(!flag) {Puts ("No Solution"); } -}

1001 number pairs in array and equal to K