third commit

main.c

@@ -0,0 +1,64 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+
+int sjfu()
+{   srand( (unsigned)time( NULL ));
+    return rand()%2;
+}
+int main()
+{
+    char a[]={'+','-'};
+    int b,c,d,t,i,j,f;
+    int daan,fenshu=0;
+    for(i=0;i<10;i++)
+    {
+        srand( (unsigned)time( NULL ));
+        b=rand()%50;
+        c=rand()%50;
+        d=sjfu();
+        if(b<c)
+        {   t=b;b=c;c=t;}
+
+        switch(a[d])
+        {
+        case '+':{daan=b+c;break;}
+        case '-':{daan=b-c;break;}
+        }                                                      //得出算式答案
+
+        if(daan>50)
+        {   i-=1;continue;}                                    //判断算式是否符合要求
+
+        printf("\t%d%c%d=?\n",b,a[d],c);                           //形成随机算式，并输出
+
+
+        for(j=0;j<3;j++)
+        {
+        scanf("%d",&f);
+        if(f==daan)
+            break;
+        else
+            printf("答案不对哦，再想想看~\n");
+        }                                                      //用户输入答案
+
+        switch(j)
+        {
+            case 0:{fenshu+=10;break;}
+            case 1:{fenshu+=7;break;}
+            case 2:{fenshu+=5;break;}
+            case 3:{fenshu+=0;printf("%d\n",daan);break;}
+        }                                                      //判断得分或输出该算式答案
+
+    }
+    if(fenshu>=90)
+        printf("SMART\n");
+    else if(fenshu<90&&fenshu>=80)
+        printf("GOOD\n");
+    else if(fenshu<80&&fenshu>=70)
+        printf("OK\n");
+    else if(fenshu<70&&fenshu>=60)
+        printf("PASS\n");
+    else
+        printf("TRY AGAIN\n");                                 //判断等级
+    return 0;
+}