second best 题解

#include <stdio.h>
#include <stdlib.h>
int compare(const void *a, const void *b) {
    return (*(int *)a - *(int *)b);
}

int main() {
    int n, m;
    scanf("%d", &n);
    int *arr = (int *)malloc(n * sizeof(int));
    if (arr == NULL) {
        printf("内存分配失败\n");
        return 1;
    }for (int i = 0; i < n; i++) {
        scanf("%d", &arr[i]);
    }
    scanf("%d", &m);
    qsort(arr, n, sizeof(int), compare);
    int left = 0, right = n - 1;
    int found = 0;
    
    while (left < right) {
        int sum = arr[left] + arr[right];
        
        if (sum == m) {
            printf("%d %d\n", arr[left], arr[right]);
            found = 1;
            break;
        } else if (sum < m) {
            left++;
        } else {
            right--;
        }
    }
    
    if (!found) {
        printf("No\n");
    }free(arr);
    return 0;
}