scanf无法读取输入的问题

Question

These were the instructions:
Write a program that starts out asking the user for the mean u and standard deviation s for the normal distribution (see the wiki article http://en.wikipedia.org/wiki/Normal_distribution ) The program then asks for an N, and then asks for N values x. For each x it writes out f(x) to the screen. Note that the program asks the user for u, s, and N just once. After that it asks for N values for x, one by one. After each value x it writes out the corresponding value of the function.

And this is my code:

#include <stdio.h>

#define PI 3.141592653589793238462643383
#define E 2.7182818284590452353602874713526624977572470937
#include <math.h>
#include <stdlib.h>

int main()
{
    double u,s, N, x1,math1, math2, math3,n, v, x;
    printf("Enter Mean: \n");
    scanf("%d", &u);
    printf("Enter Standard Deviation: \n");
    scanf("%d", &s);
    printf("Enter number of x's \n");
    scanf("%d", &N);

for (v=1; v<=N; v++)
{
     printf("Enter Value \n");
     scanf("%d", &x);
     n=1/2;
         math1 =1/(u*sqrt(2*PI));
         math2= (x-u)/s * (x-u)/s;
         math3= E * exp(n);
         x1 = math1 * exp(math3)*exp(math2);
         printf("%d \n", x1);
    }
    system("Pause");
 }

My program just stops after "Enter number of X's. Can anyone help me figure out why this is?

Answer 1

Passing incorrect format strings to scanf() invokes undefined behvaiour. All format specifiers should be %lf as the values are double :

scanf("%lf", &u);

etc.

Due to this the for loop is not entered and stops at pause .