pascalTriangle.cpp

#include "stdio.h"
#include <cmath>
#include <iostream>
#include <vector>
#include <sstream>
#include <iomanip>

typedef std::vector<int> VI;
typedef std::vector<VI> VVI;

#define dump(x)  cerr << #x << " = " << (x) << endl;
#define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl;

using namespace std;

VVI solve(int n){
	VVI v;
	v.resize(n);
	if (n < 0){
		exit(EXIT_FAILURE);
	}
	if (n == 1){
		v[0].push_back(1);
	}else if (n == 2){
		v[0].push_back(1);
		v[1].push_back(1);
		v[1].push_back(1);
	}else {
		v[0].push_back(1);
		v[1].push_back(1);
		v[1].push_back(1);
		for(int i = 2; i < n; i++){
			v[i].resize(i + 1);
		}
		for(int i = 1; i < n;i++){
			for(int j = 0; j < i + 1; j++){
				if(j == 0)
					v[i][j] = 1;
				else if(j == i)
					v[i][j] = 1;
				else
					v[i][j] = v[i - 1][j - 1] + v[i - 1][j];
			}
		}
	}
	return v;
}

int calcDigit(int n){
	return (int)log10(n) + 1;
}

void pretty_print(int n, VVI &v, int digit_max){
	string space = string(digit_max, ' ');
	cout.width(digit_max);
	cout.fill(' ');
	for(unsigned int i = 0; i < v.size(); i++){
		for(int space_i = n - i - 1; space_i > 0; space_i--){
			cout << space;
		}
		for(unsigned int j = 0; j < v[i].size(); j++){
			cout << setw(digit_max) << v[i][j] << space;
		}
		for(int space_i = n - i - 1; space_i > 0; space_i--){
			cout << space;
		}
		cout << endl;
	}
}

int main(){
	int n;
	scanf("%d", &n);
	VVI v;
	v.resize(n);
	v = solve(n);

	int isize = v.size() - 1;
	int jsize = v[isize].size() / 2;
	int max_num = v[isize][jsize];
	int digit_width = calcDigit(max_num);

	pretty_print(n, v, digit_width);
	return 0;
}

/*
実行結果
> g++ pascalTriangle.cpp
> ./a.out
10
                           1
                        1     1
                     1     2     1
                  1     3     3     1
               1     4     6     4     1
            1     5    10    10     5     1
         1     6    15    20    15     6     1
      1     7    21    35    35    21     7     1
   1     8    28    56    70    56    28     8     1
1     9    36    84   126   126    84    36     9     1
*/