大佬们，我这是有啥问题吗，编译没问题，执行就失败，提示已停止工作

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>

void ensure_input( const char* tip, const char* err_tip, int success_num, const char *restrict fmt, ... )
{
    while( 1 )
    {
        printf( "%s", tip );

        va_list ap;
        va_start( ap, fmt );
        int rc = vscanf( fmt, ap );
        va_end( ap );

        if( rc == -1 )
            exit( 1 );
        if( rc == success_num )
            break;
        scanf( "%*[^\n]%*c" );
        printf( "%s", err_tip );
    }
}

int main( void )
{
    size_t num;
    ensure_input( "请输入要排序几位数: ", "您的输入有误，请重新输入！\n", 1, "%zu", &num );

    int* array = malloc( num * sizeof(*array) );
    if( !array )
    {
        puts( "内存空间不足，退出." );
        return 1;
    }

    printf( "请输入要排序的数：\n" );
    for( size_t i=0; i!=num; ++i )
        ensure_input( "", "您的输入有误，请重新输入！\n", 1, "%d", &array[i] );

    printf( "你输入的数分别是：" );
    for( size_t i=0; i!=num; ++i )
        printf( "%d%c", array[i], " \n"[i+1==num] );

    free( array );
    return 0;
}