Gauss | Numerik

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

float A[100][100];
float x[100];
int n;

void tampil()
{
    static int i,j;
    for(i=0;i<n;i++)
    {
        for(j=0;j<n+1;j++)
        {
            printf("%3g",A[i][j]);
        }
        printf("\n");
    }
    printf("\n");
}

void masukkan()
{
    int i,j;
    float v[100],temp,tempa[100][100];

    printf(" Masukkan ukuran matriks : "); scanf("%d",&n);
    puts("----------------------------------------");

    for(i=0;i<n;i++){
        for(j=0;j<n;j++) {
            printf(" matrik A[%d][%d] = ",i+1,j+1);
            scanf("%f",&A[i][j]);
            A[i][j] = A[i][j];
        }
    }

    puts("----------------------------------------");
    printf(" Masukkan vektor matriks : \n");
    puts("----------------------------------------");

    for(i=0;i<j;i++) {
        printf(" vektor [%d] = ",i+1);
        scanf("%f",&v[i]);
        A[i][j] = v[i];
    }

    /* pengecekan tukar baris */
    for(i=0;i<n;i++) {
        temp = i;
        if(A[0][0] == 0) {
            for(j=0;j<=n;j++){
                tempa[i][j] = A[0][j];
            }
            for(j=0;j<=n;j++){
                A[0][j] = A[i+1][j];
            }
            for(j=0;j<=n;j++){
                A[i+1][j] = tempa[i][j];
            }
        }
        i = temp;
    }
    /* pengecekan tukar baris */

    printf("\n Matriks awal:\n");
    puts("----------------------------------------");
    tampil();
}

void main()
{
    int i,j,k;
    float sigma,c,b[100];

    puts("========================================");
    puts(" METODE ELIMINASI GAUSS");
    puts("========================================");

    masukkan();

    for(i=0;i<n-1;i++) {
        for(j=i+1;j < n;j++){
            c = A[j][i] / A[i][i];
            for(k=0;k<n+1;k++) {
                A[j][k] = A[j][k] - c * A[i][k];
            }
        }
    }

    for(i=0;i<n;i++){
        b[i] = A[i][n];
    }

    x[n-1] = b[n-1]/A[n-1][n-1];

    for(k=n-2;k >= 0;k--) {
        sigma = 0;
        for(j=k+1;j < n ;j++) {
            sigma = sigma + A[k][j] * x[j];
        }
        x[k] = (b[k] - sigma) / A[k][k];
    }

    printf(" Matriks setalah dilakukan OBE\n");
    puts("----------------------------------------");
    tampil();

    printf(" Hasil Penyelesaian persamaan simultan\n");
    puts("----------------------------------------");
    for(i=0;i<n;i++) {
        printf("  x%d : %g\n",i+1,x[i]);
    }
}
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