第九堂实验_1

#include <stdio.h>#define N 30void main(){int xuehao[N],chengji[N],a,i,t1,t2;float ave,sum=0;printf ("请输入学生总数\n");scanf ("%d",&a);printf("请输入学号和成绩\n");for (i=0;i<a;i++){scanf ("%d %d",&xuehao[i],&chengji[i]);}for (i=0;i<a;i++){sum=sum+chengji[i];}ave=sum/a;printf ("总分为:%.2f 平均成绩为:%.2f\n",sum,ave);int c,d;{for (c=0;c<a;c++)for(int d=0;d<a-c-1;d++){if(xuehao[d]>xuehao[d+1]){t2=xuehao[d];xuehao[d]=xuehao[d+1];xuehao[d+1]=t2;t1=chengji[d];chengji[d]=chengji[d+1];chengji[d+1]=t1;}}}printf ("按照学号由小到大\n");for (c=0;c<a;c++)printf ("%d\t%d\n",xuehao[c],chengji[c]);{for (i=0;i<a;i++)for(int j=0;j<a-i-1;j++){if(chengji[j]<chengji[j+1]){t1=chengji[j];chengji[j]=chengji[j+1];chengji[j+1]=t1;t2=xuehao[j];xuehao[j]=xuehao[j+1];xuehao[j+1]=t2;}}}printf("按照成绩由高到低：\n");for (i=0;i<a;i++)printf ("%d\t%d\n",xuehao[i],chengji[i]);int x;printf ("请输入查询的学号\n");scanf ("%d",&x);for (i=0;i<a;i++){if (xuehao[i]==x)printf ("学号:%d  排名:%d  成绩%d\n",xuehao[i],(i+1),chengji[i]);}int y=0,l=0,j=0,b=0;for (i=0;i<a;i++){if (chengji[i]>=90&&chengji[i]<=100)y++;if (chengji[i]>=70&&chengji[i]<=89)l++;  if (chengji[i]>=60&&chengji[i]<=69)  j++;  if (chengji[i]>=0&&chengji[i]<=59)  b++;}printf ("优秀\t良好\t及格\t不及格\t\n");printf ("%d\t%d\t%d\t%d\t\n",y,l,j,b);printf ("%.2f%%\t%.2f%%\t%.2f%%\t%.2f%%\t\n",(float)(100*y/a),(float)(100*l/a),(float)(100*j/a),(float)(100*b/a));printf ("学号\t成绩\t\n");for (i=0;i<a;i++){printf("%d\t%d\n",xuehao[i],chengji[i]);}printf ("总分:%.2f\t平均分%.2f\t",sum,ave);}