BNU Problem A Best Matched Pair

题目链接https://acm.bnu.edu.cn/v3/statments/jag2016.pdf

思路
把乘积转换成字符串，然后暴力求解

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<algorithm>
#define ll long long
using namespace std;
int a[1005];
char s[100000000];
char str[100000000];
int main(){
    int n;
    scanf("%d",&n);
    for(int i=0;i<n;i++){
        scanf("%d",&a[i]);
    }
    int maxx=0;
    for(int i=0;i<n-1;i++){
        for(int j=i+1;j<n;j++){
            int t=a[i]*a[j];
            sprintf(s,"%d",t);
            if(t>maxx){
                int k;
                int len=strlen(s);
                for(k=0;k<len;k++){
                    if(s[k]+1!=s[k+1])
                    break;
                }
                if(k==len-1){
                    memcpy(str,s,sizeof(str));
                    maxx=t;
                }
            }           
        }
    }
    if(maxx>0)
    printf("%s\n",str);
    else if(maxx==0)
    printf("-1\n");

    return 0;
}