Leetcode-1030 Matrix Cells in Distance Order(距离顺序排列矩阵单元格)

#define pb push_back
#define _for(i,a,b) for(int i = (a);i < (b);i ++)
#define INF 0x3f3f3f3f

typedef long long ll;
const int maxn = 50003;

int readint()
{
    int t;
    scanf("%d",&t);
    return t;
}

struct k
{
    int r;
    int c;
    int diss;
    bool operator < (k b)
    {
        return diss < b.diss;
    } 
};
class Solution
{
    public:
        vector<vector<int>> allCellsDistOrder(int R, int C, int r0, int c0)
        {
            vector<k> v;
            
            _for(i,0,R)
            {
                _for(j,0,C)
                {
                    k kk;
                    kk.r = i;
                    kk.c = j;
                    kk.diss = abs(i-r0)+abs(j-c0);
                    v.pb(kk);
                }
            }
            
            sort(v.begin(),v.end());
            vector<vector<int>> rnt;
            _for(i,0,R*C)
            {
                vector<int> tmp;
                tmp.pb(v[i].r);
                tmp.pb(v[i].c);
                rnt.pb(tmp);
            }
            return rnt;
        }
};