가우스 소거법 예제 책에 적힌거 그대로 적었는데 안됭 ㅠㅜ

사용 프로그램은 VS2012 C++ 이구...

오류뜨는거는 사진 올린거 저거야...ㅠㅜ

이거 왜 안되는 지좀 가르켜줘...




#include "stdafx.h"
#include "stdio.h"

void main()
{
        int i,j,k,num_eq, num_var;
        float coeff[20] [20], known[20];

        printf("Enter the Number of Equations. : ");
        scanf_f("%d",&num_eq);
        printf("Enter the Number of Variables. : ");
        scanf_f("%d",&num_var);
        for(i=0; i<num_eq; i++){
                printf("*********************n");
                printf("Enter the Coefficients of eq. %d. n", i+1);
                for(j=0; j<num_var; j++){
                        printf("coefficient of variable %d. : ", j+1);
                        scanf_f("%f",&coeff[i][j]);
                }
                printf("Enter the Known Value of eq. %d. : ",i+1);
                scanf_f("%f",&known[i]);
        }
        printf("********************************n");

        printf("nn Entered Equations :n");
        for(i=0;i<num_eq; i++){
                for(j=0; j<num_var; j++){
                        printf("%10.3f * X%d", coeff[i][j], j+1);
                        if(j!=num_var-1) printf("+");
                        else printf("=");
                }
                printf("%10.3fn",known[i]);
        }


        gauss_jordan_pivoting(coeff,known,num_eq,num_var);

        printf("nn**********************************n");
        printf("Results : n");
        for(i=0;i<num_eq; i++){
                for(j=0; j<num_var; j++)
                        printf("%10.3f * X%d ", coeff [i][j], j+1);
                printf("= %10.3fn", known[i]);
        }
}

void gauss_jordan_pivoting(coeff,known,num_eq, num_var)

        float coeff[20][20], known[20];
int num_eq, num_var;
{
        int pivot_eq, eq2, var, max_index;
        float max_value, ftemp;

        for (pivot_eq=0; pivot_eq<num_eq; pivot_eq++){

                max_index=0;
                max_value=coeff[pivot_eq][0];
                for(var=0; var<num_var; var++)

if(coeff[pivot_eq][var]*coeff[pivot_eq][var]>max_value*max_value){
                
                max_index=var;
                max_value=coeff[pivot_eq][var];
}


for(var=0; var<num_var;var++)
        coeff[pivot_eq][var]/=max_value;
known[pivot_eq]/=max_value;


for(eq2=0; eq2<num_eq; eq2++){
        ftemp=coeff[eq2][max_index];
        if(eq2!=pivot_eq){
                for(var=0; var<num_var; var++)

                        
coeff[eq2][var] -=ftemp*coeff[pivot_eq][var];
                                        known[eq2]-=ftemp*known[pivot_eq];
        }
}
        }
}