关于帕斯卡三角，不做过多论述，可以先查看百度百科以及leetcode。我将演示几种常用方法打印帕斯卡三角。相较于官方题解我会写的更加易懂，便于读者学习。

  1. 解法1，使用数组存储每一列（如果你没有学习过组合数学，这是一种常用解法）

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    #include <stdio.h>

    #define MAX 10

    int main() {
        int pascal[MAX][MAX] = {0}; 
        int rows, i, j;

        printf("Enter the number of rows: ");
        scanf("%d", &rows);

        
        for (i = 0; i < rows; i++) {
            pascal[i][0] = 1; 
            pascal[i][i] = 1; 

            for (j = 1; j < i; j++) {
                pascal[i][j] = pascal[i-1][j-1] + pascal[i-1][j]; 
            }
        }

        
        for (i = 0; i < rows; i++) {
            
            for (j = 0; j < rows - i; j++) {
                printf("  ");
            }
            
            for (j = 0; j <= i; j++) {
                printf("%4d", pascal[i][j]);
            }
            printf("\n");
        }

        return 0;
    }

    另附leetcode的官方题解：

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    int** generate(int numRows, int* returnSize, int** returnColumnSizes) {
        int** c = malloc(numRows * sizeof(int*));
        *returnSize = numRows;
        *returnColumnSizes = malloc(numRows * sizeof(int));
        for (int i = 0; i < numRows; i++) {
            (*returnColumnSizes)[i] = i + 1;
            c[i] = malloc((i + 1) * sizeof(int));
            c[i][0] = c[i][i] = 1;
            for (int j = 1; j < i; j++) {
                
                c[i][j] = c[i - 1][j - 1] + c[i - 1][j];
            }
        }
        return c;
    }




  2. 解法2，使用二项式系数公式单独计算每一个值

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    #include <stdio.h>


    int binomialCoeff(int n, int k);

    int main() {
      int rows, coef;

      
      printf("Enter the number of rows: ");
      scanf("%d", &rows);

      
      for (int i = 0; i < rows; i++) {
        
        for (int space = 1; space <= rows - i; space++)
          printf("  ");

        
        for (int j = 0; j <= i; j++) {
          coef = binomialCoeff(i, j);
          printf("%4d", coef);
        }
        printf("\n");
      }

      return 0;
    }


    int binomialCoeff(int n, int k) {
      int res = 1;
      if (k > n - k)
        k = n - k;
      for (int i = 0; i < k; ++i) {
        res *= (n - i);
        res /= (i + 1);
      }
      return res;
    }

  3. 解法3，基于解法2，我们也许还可以用递归来写

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    #include <stdio.h>


    void printPascalTriangle(int rows, int row);
    int binomialCoeff(int n, int k);

    int main() {
      int rows;

      
      printf("Enter the number of rows: ");
      scanf("%d", &rows);

      
      printPascalTriangle(rows, 0);

      return 0;
    }


    void printPascalTriangle(int rows, int row) {
      
      if (row >= rows)
        return;

      
      for (int space = 0; space < rows - row - 1; space++) {
        printf("  ");
      }

      
      for (int j = 0; j <= row; j++) {
        printf("%4d", binomialCoeff(row, j));
      }
      printf("\n");

      
      printPascalTriangle(rows, row + 1);
    }


    int binomialCoeff(int n, int k) {
      int res = 1;
      if (k > n - k)
        k = n - k;
      for (int i = 0; i < k; ++i) {
        res *= (n - i);
        res /= (i + 1);
      }
      return res;
    }