---

Lỗi biên dịch:

Main.cc: In function ‘int main()’:
Main.cc:7:5: error: ‘unsinged’ was not declared in this scope
     unsinged int n;
     ^~~~~~~~
Main.cc:7:5: note: suggested alternative: ‘unsigned’
     unsinged int n;
     ^~~~~~~~
     unsigned
Main.cc:8:17: error: ‘n’ was not declared in this scope
     scanf("%u",&n);
                 ^
Main.cc:8:17: note: suggested alternative: ‘yn’
     scanf("%u",&n);
                 ^
                 yn
Main.cc:15:9: error: expected ‘;’ before ‘temp’
         temp=(float)c / (2 * i + 1);
         ^~~~
Main.cc:17:20: error: ‘temp’ was not declared in this scope
     float PI = 4 * temp;
                    ^~~~
Main.cc:17:20: note: suggested alternative: ‘mktemp’
     float PI = 4 * temp;
                    ^~~~
                    mktemp
Main.cc:9:9: warning: unused variable ‘i’ [-Wunused-variable]
     int i=0;
         ^
Main.cc:10:10: warning: unused variable ‘b’ [-Wunused-variable]
     long b=0;
          ^