View Compilation Error

0_0_35759043_5018.cpp: In function 'int main()':
0_0_35759043_5018.cpp:17:24: error: 'scanf' was not declared in this scope
    while(~scanf("%d",&t)){
                        ^
0_0_35759043_5018.cpp:33:9: error: 'll' was not declared in this scope
         ll ans=0;
         ^
0_0_35759043_5018.cpp:34:24: error: 'sort' was not declared in this scope
         sort(a,a+n,cmp1);
                        ^
0_0_35759043_5018.cpp:41:21: error: 'ans' was not declared in this scope
                     ans+=(a[i]-sum[j].b);
                     ^
0_0_35759043_5018.cpp:60:13: error: 'ans' was not declared in this scope
             ans+=a[i];
             ^
0_0_35759043_5018.cpp:63:35: error: 'printf' was not declared in this scope
         printf("Case %d: ",case1++);
                                   ^
0_0_35759043_5018.cpp:64:25: error: 'ans' was not declared in this scope
         printf("%lld\n",ans);
                         ^