C++输出各种样式的三角形

*示例一（号直角三角形）

#include <iostream>
using namespace std;int main()
{int rows;cout << "输入行数: ";cin >> rows;for(int i = 1; i <= rows; ++i){for(int j = 1; j <= i; ++j){cout << "* ";}cout << "\n";}return 0;
}

输出结果

*
* *
* * *
* * * *
* * * * *

示例二（数字直角三角形）

#include <iostream>
using namespace std;int main()
{int rows;cout << "输入行数: ";cin >> rows;for(int i = 1; i <= rows; ++i){for(int j = 1; j <= i; ++j){cout << j << " ";}cout << "\n";}return 0;
}

输出结果

1
1 2
1 2 3
1 2 3 4
1 2 3 4 5

示例三（字母直角三角形）

#include <iostream>
using namespace std;int main()
{char input, alphabet = 'A';cout << "输入最后一个大写字母: ";cin >> input;for(int i = 1; i <= (input-'A'+1); ++i){for(int j = 1; j <= i; ++j){cout << alphabet << " ";}++alphabet;cout << endl;}return 0;
}

输出结果

A
B B
C C C
D D D D
E E E E E

*示例四（号倒直角三角形）

#include <iostream>
using namespace std;int main()
{int rows;cout << "输入行数: ";cin >> rows;for(int i = rows; i >= 1; --i){for(int j = 1; j <= i; ++j){cout << "* ";}cout << endl;}return 0;
}

输出结果

* * * * *
* * * *
* * * 
* *
*

示例五（数字倒直角三角形）

#include <iostream>
using namespace std;int main()
{int rows;cout << "输入行数: ";cin >> rows;for(int i = rows; i >= 1; --i){for(int j = 1; j <= i; ++j){cout << j << " ";}cout << endl;}return 0;
}

输出结果

1 2 3 4 5
1 2 3 4 
1 2 3
1 2
1

*示例六（号等腰三角形）

#include <iostream>
using namespace std;int main()
{int space, rows;cout <<"输入行数: ";cin >> rows;for(int i = 1, k = 0; i <= rows; ++i, k = 0){for(space = 1; space <= rows-i; ++space){cout <<"  ";}while(k != 2*i-1){cout << "* ";++k;}cout << endl;}    return 0;
}

输出结果

        ** * ** * * * ** * * * * * *
* * * * * * * * *

示例七（数字等腰三角形）

#include <iostream>
using namespace std;int main()
{int rows, count = 0, count1 = 0, k = 0;cout << "输入行数: ";cin >> rows;for(int i = 1; i <= rows; ++i){for(int space = 1; space <= rows-i; ++space){cout << "  ";++count;}while(k != 2*i-1){if (count <= rows-1){cout << i+k << " ";++count;}else{++count1;cout << i+k-2*count1 << " ";}++k;}count1 = count = k = 0;cout << endl;}return 0;
}

输出结果

       12 3 23 4 5 4 34 5 6 7 6 5 4
5 6 7 8 9 8 7 6 5

*示例八（号倒等腰三角形）

#include <iostream>
using namespace std;int main()
{int rows;cout << "输入行数: ";cin >> rows;for(int i = rows; i >= 1; --i){for(int space = 0; space < rows-i; ++space)cout << "  ";for(int j = i; j <= 2*i-1; ++j)cout << "* ";for(int j = 0; j < i-1; ++j)cout << "* ";cout << endl;}return 0;
}

输出结果

* * * * * * * * ** * * * * * ** * * * ** * **

示例九（数字等边三角形）

#include <iostream>
using namespace std;int main()
{int rows, coef = 1;cout << "Enter number of rows: ";cin >> rows;for(int i = 0; i < rows; i++){for(int space = 1; space <= rows-i; space++)cout <<"  ";for(int j = 0; j <= i; j++){if (j == 0 || i == 0)coef = 1;elsecoef = coef*(i-j+1)/j;cout << coef << "   ";}cout << endl;}return 0;
}

输出结果

           11   11   2   11   3   3    11  4    6   4   11  5   10   10  5   1

示例十（数字三角形）

#include <iostream>
using namespace std;int main()
{int rows, number = 1;cout << "输入行数: ";cin >> rows;for(int i = 1; i <= rows; i++){for(int j = 1; j <= i; ++j){cout << number << " ";++number;}cout << endl;}return 0;
}

输出结果

1
2 3
4 5 6
7 8 9 10

*示例十一（号长等腰三角形）

#include <iostream>
using namespace std;int main()
{int space, rows = 5;for(int i = 1; i <= rows; ++i){for(space = 1; space <= rows-i; ++space){cout <<"  ";}int k = 2*(i-1)+1;while(k>0){cout << "* ";--k;}cout << endl;}    return 0;
}

输出结果

        * * * * * * * * * * * * * * * * * * * * * * * * *