PATA1048题解

#include<iostream>
#include<vector>
#include<algorithm>
#include<cstring>
#include<map>
#include<set>
#include<cstring>
#include<stdio.h>
#include<queue>
using namespace std;

typedef pair<int,int> P;
const int MAXN = 1e5+99;
int sum[MAXN], val[MAXN];
vector<int> vec;
vector<P> res;
int N, M, MIN=1e9;
int main() {
	int num;
	cin >> N >> M;
	for(int i = 0; i < N;i++) {
		cin >> num;
		vec.push_back(num);
	}
	sort(vec.begin(), vec.end());
	int i = 0, j = N-1;
	while(i < j) {
		if(vec[i] + vec[j] == M) {
			cout << vec[i] << " " << vec[j];
			return 0;
		}else if(vec[i] + vec[j] < M) {
			i++;
		}else {
			j--;
		}
	}
	cout << "No Solution";
}

　　双指针法的应用