diff --git a/c3函数功能 b/c3函数功能
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+//3 函数功能：计算每门课程的总分和平均分 
+void  AverSumofEveryCourse(STU stu[], int n, int m)
+{
+    int i, j;
+    float sum[COURSE_NUM], aver[COURSE_NUM];
+    for (j=0; j<m; j++)
+    {
+        sum[j] = 0;
+        for (i=0; i<n; i++)
+        {
+            sum[j] +=  stu[i].score[j];
+        }
+        aver[j]=sum[j]/i;
+        printf("student %d: sum = %.0f, aver = %.0f\n", 
+j+1, sum[j], aver[j]); 
+    }
+}
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