标签：scan col algo space turn == else main efi
给出一个整数K和一个无序数组A，A的元素为N个互不相同的整数，找出数组A中所有和等于K的数对。例如K = 8，数组A：{-1,6,5,3,4,2,9,0,8}，所有和等于8的数对包括(-1,9)，(0,8)，(2,6)，(3,5)。
枚举一个二分一个，很优秀。
#include <stdio.h> #include <iostream> #include <string> #include <cstring> #include <algorithm> using namespace std; #define LL long long #define N 50001 #define INF 0x7f7f7f7f int a[N]; int n, k; int cmp(int a, int b) { return a < b; } int find(int lf, int rt, int x) { int l = lf, r = rt; int m = (l + r) >> 1; if (a[m] == x) return 1; while (l < r) { if (a[l] > x || a[r] < x) return 0; if (a[m] > x) r = m - 1; else if (a[m] < x) l = m + 1; m = (l + r) >> 1; if (a[m] == x) return 1; } return 0; } int main() { scanf("%d%d", &k, &n); for (int i = 1; i <= n; i++) scanf("%d", &a[i]); sort(a + 1, a + n + 1, cmp); bool fl = 0; for (int i = 1; i <= n; i++) { if (find(i + 1, n, k - a[i])) { printf("%d %d\n", a[i], k - a[i]); fl = 1; } } if (!fl) printf("No Solution\n"); }
标签：scan col algo space turn == else main efi
原文地址：http://www.cnblogs.com/nidhogg/p/8006966.html
