View Compilation Error

0_0_19741346_3651.cpp:1:8: error: 'N' was not declared in this scope
 int fa[N], Rank[N];//Rank数组表示集合的秩
        ^
0_0_19741346_3651.cpp:1:17: error: 'N' was not declared in this scope
 int fa[N], Rank[N];//Rank数组表示集合的秩
                 ^
0_0_19741346_3651.cpp: In function 'void init(int)':
0_0_19741346_3651.cpp:6:9: error: 'fa' was not declared in this scope
         fa[i] = i;
         ^
0_0_19741346_3651.cpp:7:9: error: 'Rank' was not declared in this scope
         Rank[i] = 1;
         ^
0_0_19741346_3651.cpp: In function 'int find(int)':
0_0_19741346_3651.cpp:12:17: error: 'fa' was not declared in this scope
     return x == fa[x] ? x : fa[x] = find(fa[x]);
                 ^
0_0_19741346_3651.cpp: In function 'void unio(int, int)':
0_0_19741346_3651.cpp:19:9: error: 'Rank' was not declared in this scope
     if (Rank[y1] < Rank[y2])
         ^
0_0_19741346_3651.cpp:21:9: error: 'fa' was not declared in this scope
         fa[y1] = y2;
         ^
0_0_19741346_3651.cpp:26:9: error: 'fa' was not declared in this scope
         fa[y2] = y1;
         ^