Add step3

step3

@@ -0,0 +1,36 @@
+#include<stdio.h>
+
+int main()
+{
+	printf("                              1.Input\n");
+	printf("                              2.Output\n");
+	printf("                              3.Order\n");
+	printf("                              4.Quit\n");
+	
+	char x;
+	scanf("%c",&x);
+	switch(x){
+		case 'o':printf("You are trying to Output info");break;
+		case 'm':printf("You are trying to Make things ordered");break;
+		case 'q':printf("You are about to Quit");break;
+		case 'i':printf("Please input info of the three students:");
+			int i=0;
+			int stn[3];
+			float gsc[3],dwc[3],eyc[3],sum[3];
+			
+			for(i=0;i<3;i++){
+				scanf("%d",&stn[i]);
+				scanf("%f",&gsc[i]);
+				scanf("%f",&dwc[i]);
+				scanf("%f",&eyc[i]);
+			}
+			for(i=0;i<3;i++){
+				sum[i]=gsc[i]+dwc[i]+eyc[i]; 
+		    }
+		    //缺排序加输出 
+			
+		break;
+		default:printf("Wrong input\n");break;
+	}
+	return 0;
+}