#include

int main()

{

float score;

while(1)

{

printf("請輸入一個成績：\n");

scanf("%f",&score);

if(score100)

printf("成績輸入錯誤！\n");

else if(score>=0&&score

printf("成績等級為E\n");

else if(score>=60&&score

printf("成績等級為D\n");

else if(score>=70&&score

printf("成績等級為C\n");

else if(score>=80&&score

printf("成績等級為B\n");

else if(score>=90&&score

printf("成績等級為A\n");

}

return 0;

}