1 #define pb push_back
 2 #define _for(i,a,b) for(int i = (a);i < (b);i ++)
 3 #define INF 0x3f3f3f3f
 4 
 5 typedef long long ll;
 6 const int maxn = 50003;
 7 
 8 int readint()
 9 {
10     int t;
11     scanf("%d",&t);
12     return t;
13 }
14 
15 struct k
16 {
17     int r;
 
18     int c;
19     int diss;
20     bool operator < (k b)
21     {
22         return diss < b.diss;
23     } 
24 };
25 class Solution
26 {
27     public:
28         vector<vector<int>> allCellsDistOrder(int R, int C, int r0, int c0)
29         {
30             vector<k> v;
 
31             
32             _for(i,0,R)
33             {
34                 _for(j,0,C)
35                 {
36                     k kk;
37                     kk.r = i;
38                     kk.c = j;
39                     kk.diss = abs(i-r0)+abs(j-c0);
40                     v.pb(kk);
41
 
                 }
42             }
43             
44             sort(v.begin(),v.end());
45             vector<vector<int>> rnt;
46             _for(i,0,R*C)
47             {
48                 vector<int> tmp;
49                 tmp.pb(v[i].r);
50                 tmp.pb(v[i].c);
51                 rnt.pb(tmp);
52             }
53             return rnt;
54         }
55 };

Leetcode-1030 Matrix Cells in Distance Order(距離順序排列矩陣單元格)