runner% cat graph_two_dim.c
#include <stdio.h>
#include <math.h>
#define ROWS 101
#define COLS 62
#define PI 3.14159265358979

double f(double x, int n);
void init_d(char d[][COLS]);
void display_d(char d[][COLS]);
void display2_d(char d[][COLS]);

void main(void)
{
	int i, j;
	double x = 0.0;
	char d[ROWS][COLS];
	int n;
	scanf("%d", &n);
	init_d(d);
	for (i = 0; i < ROWS; i++) {
		j = (int)(50*f(x, n));
		if (j < 0) d[i][0] = '*';
		else if (j > 61) d[i][61] = '*';
		else d[i][j] = '+';
		x = x + (1.0/30.0);
	}
	display_d(d);
	printf("\n------------------------------------------\n\n");
	display2_d(d);
}
double f(double x, int n)
{
	int i;
	double sum = 0.0;
	double sign = 1.0;
	for (i = 1; i <= n; i++) {
		sum = sum + (sign/i)*sin(i*x);
		sign = -sign;
	}
	return (2.0/PI)*sum;
}
void init_d(char d[][COLS])
{
	int i, j;
	for (i = 0; i < ROWS; i++)
		for (j = 0; j < COLS; j++)
			d[i][j] = ' ';
}
void display_d(char d[][COLS])
{
	int i, j;
	for (i = 0; i < ROWS; i++) {
		if ((i%6) == 0) printf("%4.1f-", i*(1.0/30.0));
		else printf("    |");
		for (j = 0; j < COLS; j++)
			printf("%c", d[i][j]);
		printf("\n");
	}
}
void display2_d(char d[][COLS])
{
	int i, j;
	for (j = COLS - 2; j >= 0; j--) {
		if ((j%10) == 0) printf("%4.1f-", j*(1.0/50.0));
		else printf("    |");
		for (i = 0; i < ROWS; i++)
			printf("%c", d[i][j]);
		printf("\n");
	}
}
runner% cc -o graph_two_dim graph_two_dim.c -lm
runner% graph_two_dim
10	











 0.0-+                                                             
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 1.0-                 +                                            
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 1.2-                  +                                           
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 1.4-                    +                                         
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 1.6-                           +                                  
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 2.0-                             +                                
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 2.6-                                     +                        
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 2.8-                                                    +         
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 3.0-                                       +                      
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    |*                                                             
 3.2-*                                                             
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 1.2-                                                                                                     
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 1.0-                                                                                   +    +            
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 0.8-                                                                                                     
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 0.6-                                                             +                                       
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 0.4-                                          +                                                          
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 0.0-+++++                                                                                          ******