View Compilation Error

0_0_18721569_18690.cpp: In function 'int main()':
0_0_18721569_18690.cpp:14:18: error: 'inf' was not declared in this scope
         int max=-inf;
                  ^
0_0_18721569_18690.cpp:17:25: error: 'a' was not declared in this scope
             scanf("%d",&a[i]);
                         ^
0_0_18721569_18690.cpp:25:32: error: 'a' was not declared in this scope
             printf("0 %d %d\n",a[0],a[n-1]);
                                ^
0_0_18721569_18690.cpp:31:22: error: 'a' was not declared in this scope
                 sum+=a[i];
                      ^
0_0_18721569_18690.cpp:44:37: error: 'a' was not declared in this scope
             printf("%d %d %d\n",max,a[y],a[k]);
                                     ^