foo.cc: In function 'int main()':
foo.cc:7:35: error: expected ')' before '\U0000ff09'
    7 |         for (int i = 0; i < n; i++）
      |             ~                     ^~
      |                                   )
foo.cc:7:35: error: '\U0000ff09' was not declared in this scope
    7 |         for (int i = 0; i < n; i++）
      |                                   ^~
foo.cc:5:13: warning: unused variable 'a' [-Wunused-variable]
    5 |         int a = 1; int b = 1; int c = 0; int n = 0; int n1 = 1; int n2 = 2; int sum = 0;//n为项数
      |             ^
foo.cc:5:24: warning: unused variable 'b' [-Wunused-variable]
    5 |         int a = 1; int b = 1; int c = 0; int n = 0; int n1 = 1; int n2 = 2; int sum = 0;//n为项数
      |                        ^
foo.cc:5:35: warning: unused variable 'c' [-Wunused-variable]
    5 |         int a = 1; int b = 1; int c = 0; int n = 0; int n1 = 1; int n2 = 2; int sum = 0;//n为项数
      |                                   ^

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