fgets not waiting for user input - c

Question

In the given code fgets is not waiting for input.
I tried using scanf but it's giving unusual error(Exception thrown at 0x0F74DDF4 (ucrtbased.dll)). I'm using Visual Studio 2015 for debugging my code. Can anyone explain why fgets is not waiting for input?
#include<stdio.h>
#include<stdlib.h>
#include<process.h>
//GLOBAL-VARIABLE DECLARTION
#define MAX 1000
//GLOBAL-STRUCTURES DECLARATION
struct census
{
char city[MAX];
long int p;
float l;
};
//GLOBAL-STRUCTURE-VARIABLE DECLARATION
struct census cen[] = { 0,0,0 };
//USER-DEFINED FUNCTION
void header();
void header()
{
printf("*-*-*-*-*CENSUS_INFO*-*-*-*-*");
printf("\n\n");
}
//PROGRAM STARTS HERE
main()
{
//VARIABLE-DECLARATION
int i = 0, j = 0;
//int no_of_records = 0;
//FUNCTION CALL-OUT
header();
printf("Enter No. of City : ");
scanf_s("%d", &j);
printf("\n\n");
printf("Enter Name of City, Population and Literacy level");
printf("\n\n");
for (i = 0;i < j;i++)
{
printf("City No. %d - Info :", i + 1);
printf("\n\n");
printf("City Name :");
fgets(cen[i].city, MAX, stdin);
printf("\n");
printf("Population : ");
scanf_s("%d", &cen[i].p);
printf("\n");
printf("Literacy : ");
scanf_s("%f", &cen[i].l);
printf("\n");
}
//TERMINAL-PAUSE
system("pause");
}

Answer 1

When you enter the number of cities and press Enter, scanf doesn't read the linebreak character from input. fgets then tries to read but finds the linebreak, and immediately stops.
Don't use scanf to read numbers, use fgets to read in string first and then sscanf(or strtol/strtof/strtod) to convert to number.
char temp[LIMIT];
if(fgets(temp, LIMIT, stdin)) {
if(sscanf(temp, "%d", &j) == 1) {
// Ok
}
else {
// Handle sscanf error
}
}
else {
// Handle fgets error
}

Answer 2

I always use fgets followed by sscanf.
Declare this at the top,
char line[MAX];
Then use fgets to get a line, and sscanf to parse the int value out of it,
printf("Enter No. of City : ");
fgets(line, sizeof(line), stdin);
sscanf(line, "%d", &j);
Similar pattern for l
printf("Literacy : ");
fgets(line, sizeof(line), stdin);
sscanf(line, "%f", &cen[i].l);