将数字与数位和捆绑(使用结构体或元组)放入数组或列表,以数位和为关键字排序,最后输出第 m 个数。
#include<stdio.h>
#include<algorithm>
using namespace std;
const int MAXN=1e6+7;
struct Node{int id,num;
}l[MAXN];
int n,m,ans;
inline int Count(int x)
{int sum=0;while(x)sum+=x%10,x/=10;return sum;
}
inline bool cmp(Node A,Node B)
{return A.num==B.num?A.id<B.id:A.num<B.num;
}
int main()
{scanf("%d %d",&n,&m);for(int i=1;i<=n;i++)l[i]={i,Count(i)};sort(l+1,l+1+n,cmp);printf("%d",l[m].id);return 0;
}