View Compilation Error

0_0_35790748_6381.cpp:10:1: error: expected initializer before 'bool'
 bool vis[M];
 ^
0_0_35790748_6381.cpp: In function 'long long int gauss(long long int)':
0_0_35790748_6381.cpp:36:13: error: 'A' was not declared in this scope
         if(!A[i][i])
             ^
0_0_35790748_6381.cpp:55:19: error: 'A' was not declared in this scope
             while(A[j][i])
                   ^
0_0_35790748_6381.cpp:67:17: error: 'A' was not declared in this scope
         ans=ans*A[i][i]%mod;
                 ^
0_0_35790748_6381.cpp: In function 'int main()':
0_0_35790748_6381.cpp:81:16: error: 'vis' was not declared in this scope
         memset(vis,false,sizeof(vis));
                ^
0_0_35790748_6381.cpp:83:16: error: 'A' was not declared in this scope
         memset(A,0,sizeof(A));
                ^