View Compilation Error

0_0_14104458_23486.cpp: In function 'void getdata()':
0_0_14104458_23486.cpp:94:12: error: 'b' was not declared in this scope
     memset(b,0,sizeof(b));
            ^
0_0_14104458_23486.cpp:95:19: error: 'n' was not declared in this scope
     scanf("%d%d",&n,&m);
                   ^
0_0_14104458_23486.cpp:95:22: error: 'm' was not declared in this scope
     scanf("%d%d",&n,&m);
                      ^
0_0_14104458_23486.cpp: In function 'int main()':
0_0_14104458_23486.cpp:111:22: error: 'b' was not declared in this scope
             memcpy(a,b,sizeof(b));
                      ^
0_0_14104458_23486.cpp:112:28: error: 'n' was not declared in this scope
             for (int i=0;i<n;i++) scanf("%d",&a[i][m]);
                            ^
0_0_14104458_23486.cpp:112:52: error: 'm' was not declared in this scope
             for (int i=0;i<n;i++) scanf("%d",&a[i][m]);
                                                    ^
0_0_14104458_23486.cpp:113:28: error: 'n' was not declared in this scope
             int flag=gauss(n,m);
                            ^
0_0_14104458_23486.cpp:113:30: error: 'm' was not declared in this scope
             int flag=gauss(n,m);
                              ^