View Compilation Error

0_0_21391880_27405.cpp:5:1: error: expected initializer before 'unsigned'
 unsigned a[105],s[maxn];
 ^
0_0_21391880_27405.cpp: In function 'int main()':
0_0_21391880_27405.cpp:32:4: error: 'id' was not declared in this scope
    id[i] = i;
    ^
0_0_21391880_27405.cpp:35:23: error: 's' was not declared in this scope
   for (i=0; i<n; i++) s[i] = rng61();
                       ^
0_0_21391880_27405.cpp:36:8: error: 'id' was not declared in this scope
   sort(id,id+m,cmp);
        ^
0_0_21391880_27405.cpp:43:5: error: 'a' was not declared in this scope
     a[id[i]] = a[id[i+1]];
     ^
0_0_21391880_27405.cpp:46:16: error: 's' was not declared in this scope
    nth_element(s,s+p[id[i]],s+p[id[i+1]]);
                ^
0_0_21391880_27405.cpp:47:4: error: 'a' was not declared in this scope
    a[id[i]] = s[p[id[i]]];
    ^
0_0_21391880_27405.cpp:50:37: error: 'a' was not declared in this scope
   for (i=0; i<m; i++) printf("%u%c",a[i],(i==m-1?'\n':' '));
                                     ^