View Compilation Error

0_0_20852084_5102.cpp: In function 'int calc(int, int)':
0_0_20852084_5102.cpp:21:17: error: 'x' was not declared in this scope
     for(int i = x, j= y ; i <= n && j <= n; i ++, j ++){
                 ^
0_0_20852084_5102.cpp:21:37: error: 'j' was not declared in this scope
     for(int i = x, j= y ; i <= n && j <= n; i ++, j ++){
                                     ^
0_0_20852084_5102.cpp:23:22: error: 's' was not declared in this scope
         point[m].R = s + min(R[i][j], D[i][j]) - 1;
                      ^