Добавил исходники Матвея

2025.04.18/dist/Ulyanov_MT/task02.c

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+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <math.h>
+#include "io_status.h"
+#include "array.h"
+#include "functions.h"
+
+io_status solve2(double*, double*, double, int, double*);
+
+int main(int argc, char* argv[])
+  {
+  int task = 2;
+  io_status ret;
+  double* x;
+  double* y;
+  int n;
+  double x0;
+  char* name = 0;
+  double res;
+  double t;
+  if (!((argc == 4) && sscanf(argv[1], "%le", &x0) == 1 && sscanf(argv[2], "%d", &n) == 1))
+      {
+      printf("Usage: %s x0 n file\n", argv[0]);
+      return 1;
+      }
+  name = argv[3];
+  x = (double*) malloc(n * sizeof(double));
+  y = (double*) malloc(n * sizeof(double));
+  if ((!x) || (!y))
+      {
+      printf("Not enough memory\n");
+      if (x) free(x);
+      if (y) free(y);
+      return 2;
+      }
+  ret = read_function(x, y, n, name);
+  if (ret != SUCCESS)
+      {
+      switch(ret)
+          {
+          case ERROR_OPEN:
+              printf("Can not open file %s\n", name);
+              break;
+          case ERROR_READ:
+              printf("Can not read file %s\n", name);
+              break;
+          default:
+              printf("UNknown error in file %s\n", name);
+          }
+      free(x);
+      free(y);
+      return 3;
+      }
+  t = clock();
+  ret = solve2(x, y, x0, n, &res);
+  t = (clock() - t) / CLOCKS_PER_SEC;
+  if (ret != SUCCESS)
+      {
+      printf("Similar points in file %s\n", name);
+      free(x);
+      free(y);
+      return 4;
+      }
+  printf ("%s : Task = %d Result = %e Elapsed = %.2f\n", argv[0], task, res, t);
+  free(x);
+  free(y);
+  return 0;
+  }
+    
+io_status solve2(double* x, double* y, double x0, int n, double* res)
+  {
+  int i, j;
+  double el_n, el_prev, sum = 0;
+  for (j = 0; j < n; j++)
+      {
+      for (i = n - 1; i > j; i--)
+          {
+          el_n = x[i];
+          el_prev = x[i - j - 1];
+          if (equal(el_n, el_prev)) return ERROR_FUNCTION;
+          y[i] = (y[i] - y[i - 1]) / (el_n - el_prev);
+          }
+      }
+  for (i = n - 1; i >= 0; i--)
+      {
+      sum = y[i] + (x0 - x[i]) * sum;
+      }
+  *res = sum;
+  return SUCCESS;
+  }