diff --git a/step6.c b/step6.c
new file mode 100644
index 0000000..1417e45
--- /dev/null
+++ b/step6.c
@@ -0,0 +1,102 @@
+#include <stdio.h>
+#include <string.h>
+int main(){
+	int CORRECT(float m[][4],char m1[][6],char m2[][10],int r);
+	int SORT(float m[][4],char m1[][6],char m2[][10],int r,int t);
+	int i,j,signal;
+	float message[3][4]={{11,99.5,88.5,89.5},{12,77.9,56.5,87.5},{11,92.5,99.0,60.5}};
+	char message_number[3][6]={"10001","10002","10003"};
+	char message_name[3][10]={"Zhang","Yang","Liang"};
+	signal=CORRECT(message,message_number,message_name,3);
+	signal=SORT(message,message_number,message_name,3,signal);
+	for(i=0;i<3;i++){
+		if(i>0&&message[i-1][0]==message[i][0]){
+			printf("   ");
+		}
+		else
+			printf("%d ",(int)message[i][0]);
+		printf("%s ",message_number[i]);
+		printf("%s ",message_name[i]);
+		for(j=1;j<=2;j++){
+			printf("%.1f ",message[i][j]);
+		}
+		if(i==signal){
+			printf("%.1f modified\n",message[i][3]);
+		}
+		else{
+			printf("%.1f\n",message[i][3]);
+		}	
+	}
+}
+int CORRECT(float m[][4],char m1[][6],char m2[][10],int r){
+	int i,j,signal,word=0;
+	char number[6];
+	scanf("%5s",number);
+	number[6]='\0';
+	for(i=0;i<r&&word==0;i++){
+		if(strcmp(number,m1[i])==0){
+			scanf("%f",(*(m+i)+0));
+			scanf("%s",m2[i]);
+			for(j=1;j<=3;j++){
+				scanf("%f",(*(m+i)+j));
+			}
+			signal=i;
+			word=1;	
+		}
+	}
+	if(word==0)
+		return(r);
+	else
+		return(signal);
+}
+int SORT(float m[][4],char m1[][6],char m2[][10],int r,int t){
+	void SWAPNUMBER(float a[],float b[],int c);
+	void SWAPSTRING(char a[],char b[]);
+	int i,j,s;
+	for(i=1;i<r;i++){
+		for(j=0;j<r-i;j++){
+			if(*(*(m+j)+0)>*(*(m+j+1)+0)){
+				SWAPNUMBER(m[j],m[j+1],4);
+			    SWAPSTRING(m1[j],m1[j+1]);
+			    SWAPSTRING(m2[j],m2[j+1]);
+			    if(j==t)
+			    	t++;
+			}
+			
+			else if(*(*(m+j)+0)==*(*(m+j+1)+0)){
+				float totalscore1=*(*(m+j)+1)+*(*(m+j)+2)+*(*(m+j)+3);
+				float totalscore2=*(*(m+j+1)+1)+*(*(m+j+1)+2)+*(*(m+j+1)+3);
+				if(totalscore1<totalscore2){
+					SWAPNUMBER(m[j],m[j+1],4);
+			    	SWAPSTRING(m1[j],m1[j+1]);
+			   	    SWAPSTRING(m2[j],m2[j+1]);
+			   	    if(j==t)
+			    	t++;
+				}
+			}	
+		}
+	}
+	return(t);
+}
+void SWAPNUMBER(float a[],float b[],int c){
+	float t[c];
+	int s;
+	for(s=0;s<c;s++){
+		*(t+s)=*(a+s);
+		*(a+s)=*(b+s);
+		*(b+s)=*(t+s);
+	}
+}
+void SWAPSTRING(char a[],char b[]){
+	int l1=strlen(a),l2=strlen(b);
+	char s[20];
+	strcpy(s,a);
+	strcpy(a,b);
+	strcpy(b,s);
+	if(l1>l2){
+		a[l2]='\0';
+	}
+	else if(l1<l2){
+		b[l1]='\0';
+	}
+}