View Compilation Error

0_0_23218812_13132.cpp: In function 'int main()':
0_0_23218812_13132.cpp:55:29: error: 'scanf' was not declared in this scope
         scanf("%d%d", &n, &m);
                             ^
0_0_23218812_13132.cpp:61:30: error: 'sort' was not declared in this scope
         sort(Hash+1, Hash+n+1);
                              ^
0_0_23218812_13132.cpp:62:38: error: 'unique' was not declared in this scope
         int d=unique(Hash+1, Hash+n+1)-Hash-1;
                                      ^
0_0_23218812_13132.cpp:66:53: error: 'lower_bound' was not declared in this scope
             int x=lower_bound(Hash+1, Hash+d+1, a[i])-Hash;
                                                     ^
0_0_23218812_13132.cpp:74:35: error: 'printf' was not declared in this scope
             printf("%d\n", Hash[x]);
                                   ^
0_0_23218812_13132.cpp: At global scope:
0_0_23218812_13132.cpp:79:1: error: 'POJ' does not name a type
 POJ 2104 && HDOJ 2665 && POJ 2761
 ^