一道顺序表的实验题的反思

一开始写了个代码，输出结果表示莫名奇妙，

<img src="https://img-blog.youkuaiyun.com/20160313133738316?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQv/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center" alt="" />

#include<stdio.h>
#include<stdlib.h>
#define maxn 20

typedef struct table_type{
	int a[maxn];
	int length;
} table_type;
table_type *table;
//o123,length=4,1,2,3,4,a[2]jfrom 4 to 2,
table_type *Insert(table_type *table,int x,int i){
	int j;
	for( j=table->length;j>i-1;j--){
		table->a[j]=table->a[j-1];
	}
	table->a[--j]=x;
	table->length++; 
}

table_type *Print(table_type *table){
	for(int i=0;i<table->length;i++){
		printf("%d",table->a[i]);
	}
	printf("\n");
	return table;
	
}

void Delete(table_type *table,int x){
	int i=0;
	while(table->a[i]!=x)
		i++;
	for(int j=i;j<table->length;j++){
		table->a[j]=table->a[j+1];
	}
	table->length--;
}

int main(){
	table=(table_type*)malloc(sizeof(struct table_type));
	table->length=0;
	int i=0,t;
	while(scanf("%d",&t)==1&&t!=-1){
		table->a[i]=t;
		i++;
		table->length++;
	}
	Print(table);
	Insert(table,0,2);
	Print(table);

	
	
	
} 

后来发现，for循环里的j循环结束后的值是j-1而不是j,真是糊涂了

正确代码：

<pre name="code" class="cpp">#include<stdio.h>
#include<stdlib.h>
#define maxn 20

typedef struct table_type{
	int a[maxn];
	int length;
} table_type;
table_type *table;

table_type *Print(table_type *table){
	for(int i=0;i<table->length;i++){
		printf("%d",table->a[i]);
	}
	printf("\n");
	return table;
	
}

table_type *Insert(table_type *table,int x,int i){
	int j;
	for( j=table->length;j>i-1;j--){
		table->a[j]=table->a[j-1];
	}
	table->a[i-1]=x;
	table->length++; 
	Print(table);
}



void Delete(table_type *table,int x){
	int i=0;
	while(table->a[i]!=x)
		i++;
	for(int j=i;j<table->length;j++){
		table->a[j]=table->a[j+1];
	}
	table->length--;
	Print(table);
}

int main(){
	table=(table_type*)malloc(sizeof(struct table_type));
	table->length=0;
	int i=0,t,x;
	printf("pelase init the table\n"); 
	while(scanf("%d",&t)==1&&t!=-1){
		table->a[i]=t;
		i++;
		table->length++;
	}
	Print(table);
	printf("******************************\n"); 
	printf("|-Please enter a command code!|\n");
	printf("|input a new data ,enter 1    |\n");
	printf("|delete a data,    enter 2    |\n"); 
	printf("|quit the system,  enter 0    |\n");
	printf("******************************\n"); 
	for(;;){
	scanf("%d",&t);
	if(t==0) break;
	if(t==1){
		scanf("%d %d",&x,&i);
		Insert(table,x,i);
	} 
	else {
		scanf("%d",&x);
		Delete(table,x); 
	}
	
	}
		
	
}