C语言10大基础算法，学C语言必会源码（珍藏版）

小林C语言

修改于 2020-12-23 11:54:47

2.7K0

修改于 2020-12-23 11:54:47

算法是一个程序和软件的灵魂，作为一名优秀的程序员，只有对一些基础的算法有着全面的掌握，才会在设计程序和编写代码的过程中显得得心应手。本文是近百个C语言算法系列的第二篇，包括了经典的Fibonacci数列、简易计算器、回文检查、质数检查等算法。也许他们能在你的毕业设计或者面试中派上用场。

1、C语言计算Fibonacci数列

Fibonacci数列又称斐波那契数列，又称黄金分割数列，指的是这样一个数列：1、1、2、3、5、8、13、21。

C语言实现的代码如下：

/* Displaying Fibonacci sequence up to nth term where n is entered by user. */#include <stdio.h>int main(){int count, n, t1=0, t2=1, display=0;printf("Enter number of terms: ");scanf("%d",&n);printf("Fibonacci Series: %d+%d+", t1, t2); /* Displaying first two terms */  count=2;    /* count=2 because first two terms are already displayed. */while (count<n)    {      display=t1+t2;      t1=t2;      t2=display;      ++count;printf("%d+",display);  }return 0;}

结果输出：

Enter number of terms: 10Fibonacci Series: 0+1+1+2+3+5+8+13+21+34+

也可以使用下面的源代码：

/* Displaying Fibonacci series up to certain number entered by user. */
#include <stdio.h>int main(){int t1=0, t2=1, display=0, num;printf("Enter an integer: ");scanf("%d",&num);printf("Fibonacci Series: %d+%d+", t1, t2); /* Displaying first two terms */  display=t1+t2;while(display<num)  {printf("%d+",display);      t1=t2;      t2=display;      display=t1+t2;  }return 0;}

结果输出：

Enter an integer: 200Fibonacci Series: 0+1+1+2+3+5+8+13+21+34+55+89+144+

2、C语言回文检查

源代码：

/* C program to check whether a number is palindrome or not */
#include <stdio.h>int main(){int n, reverse=0, rem,temp;printf("Enter an integer: ");scanf("%d", &n);  temp=n;while(temp!=0)  {     rem=temp%10;     reverse=reverse*10+rem;     temp/=10;  }  /* Checking if number entered by user and it's reverse number is equal. */if(reverse==n)  printf("%d is a palindrome.",n);elseprintf("%d is not a palindrome.",n);return 0;}

结果输出：

Enter an integer: 1232112321 is a palindrome.

推荐个10天入门C/C++的公众号：C语言入门到精通

3、C语言质数检查

注：1既不是质数也不是合数。

源代码：

/* C program to check whether a number is prime or not. */
#include <stdio.h>int main(){int n, i, flag=0;printf("Enter a positive integer: ");scanf("%d",&n);for(i=2;i<=n/2;++i)  {if(n%i==0)      {          flag=1;break;      }  }if (flag==0)printf("%d is a prime number.",n);elseprintf("%d is not a prime number.",n);return 0;}

结果输出：

Enter a positive integer: 2929 is a prime number.

4、C语言打印金字塔和三角形

使用 * 建立三角形

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

源代码：

#include <stdio.h>int main(){int i,j,rows;printf("Enter the number of rows: ");scanf("%d",&rows);for(i=1;i<=rows;++i)    {for(j=1;j<=i;++j)        {printf("* ");        }printf("\n");    }return 0;}

如下图所示使用数字打印半金字塔。

11 21 2 31 2 3 41 2 3 4 5

源代码：

#include <stdio.h>int main(){int i,j,rows;printf("Enter the number of rows: ");scanf("%d",&rows);for(i=1;i<=rows;++i)    {for(j=1;j<=i;++j)        {printf("%d ",j);        }printf("\n");    }return 0;}

用 * 打印半金字塔

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

源代码：

#include <stdio.h>int main(){int i,j,rows;printf("Enter the number of rows: ");scanf("%d",&rows);for(i=rows;i>=1;--i)    {for(j=1;j<=i;++j)        {printf("* ");        }printf("\n");    }return 0;}

用 * 打印金字塔

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

源代码：

#include <stdio.h>int main(){int i,space,rows,k=0;printf("Enter the number of rows: ");scanf("%d",&rows);for(i=1;i<=rows;++i)    {for(space=1;space<=rows-i;++space)        {printf("  ");        }while(k!=2*i-1)        {printf("* ");           ++k;        }        k=0;printf("\n");    }return 0;}

用 * 打印倒金字塔

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

源代码：

#include<stdio.h>int main(){int rows,i,j,space;printf("Enter number of rows: ");scanf("%d",&rows);for(i=rows;i>=1;--i)    {for(space=0;space<rows-i;++space)printf("  ");for(j=i;j<=2*i-1;++j)printf("* ");for(j=0;j<i-1;++j)printf("* ");printf("\n");    }return 0;}

推荐个10天入门C/C++的公众号：C语言入门到精通

5、C语言实现简单的加减乘除计算器

源代码：

/* Source code to create a simple calculator for addition, subtraction, multiplication and division using switch...case statement in C programming. */# include <stdio.h>int main(){char o;float num1,num2;printf("Enter operator either + or - or * or divide : ");scanf("%c",&o);printf("Enter two operands: ");scanf("%f%f",&num1,&num2);switch(o) {case '+':printf("%.1f + %.1f = %.1f",num1, num2, num1+num2);break;case '-':printf("%.1f - %.1f = %.1f",num1, num2, num1-num2);break;case '*':printf("%.1f * %.1f = %.1f",num1, num2, num1*num2);break;case '/':printf("%.1f / %.1f = %.1f",num1, num2, num1/num2);break;default:/* If operator is other than +, -, * or /, error message is shown */printf("Error! operator is not correct");break;    }return 0;}

结果输出：

Enter operator either + or - or * or divide : -Enter two operands: 3.48.43.4 - 8.4 = -5.0

6、C语言实现检查一个数能不能表示成两个质数之和

源代码：

#include <stdio.h>int prime(int n);int main(){int n, i, flag=0;printf("Enter a positive integer: ");scanf("%d",&n);for(i=2; i<=n/2; ++i)    {if (prime(i)!=0)        {if ( prime(n-i)!=0)            {printf("%d = %d + %d\n", n, i, n-i);                flag=1;            }        }    }if (flag==0)printf("%d can't be expressed as sum of two prime numbers.",n);return 0;}int prime(int n)      /* Function to check prime number */{int i, flag=1;for(i=2; i<=n/2; ++i)if(n%i==0)          flag=0;return flag;}

结果输出：

Enter a positive integer: 3434 = 3 + 3134 = 5 + 2934 = 11 + 2334 = 17 + 17

7、C语言用递归的方式颠倒字符串

源代码：

/* Example to reverse a sentence entered by user without using strings. */
#include <stdio.h>void Reverse();int main(){printf("Enter a sentence: ");    Reverse();return 0;}void Reverse(){char c;scanf("%c",&c);if( c != '\n')    {        Reverse();printf("%c",c);    }}

结果输出：

Enter a sentence: margorp emosewaawesome program

8、C语言实现二进制与十进制之间的相互转换

/* C programming source code to convert either binary to decimal or decimal to binary according to data entered by user. */
#include <stdio.h>#include <math.h>int binary_decimal(int n);int decimal_binary(int n);int main(){int n;char c;printf("Instructions:\n");printf("1. Enter alphabet 'd' to convert binary to decimal.\n");printf("2. Enter alphabet 'b' to convert decimal to binary.\n");scanf("%c",&c);if (c =='d' || c == 'D')   {printf("Enter a binary number: ");scanf("%d", &n);printf("%d in binary = %d in decimal", n, binary_decimal(n));   }if (c =='b' || c == 'B')   {printf("Enter a decimal number: ");scanf("%d", &n);printf("%d in decimal = %d in binary", n, decimal_binary(n));   }return 0;}
int decimal_binary(int n)  /* Function to convert decimal to binary.*/{int rem, i=1, binary=0;while (n!=0)    {        rem=n%2;        n/=2;        binary+=rem*i;        i*=10;    }return binary;}
int binary_decimal(int n) /* Function to convert binary to decimal.*/{int decimal=0, i=0, rem;while (n!=0)    {        rem = n%10;        n/=10;        decimal += rem*pow(2,i);        ++i;    }return decimal;}

结果输出：

9、C语言实现使用多维数组实现两个矩阵的相加

源代码：

#include <stdio.h>int main(){int r,c,a[100][100],b[100][100],sum[100][100],i,j;printf("Enter number of rows (between 1 and 100): ");scanf("%d",&r);printf("Enter number of columns (between 1 and 100): ");scanf("%d",&c);printf("\nEnter elements of 1st matrix:\n");
/* Storing elements of first matrix entered by user. */
for(i=0;i<r;++i)for(j=0;j<c;++j)       {printf("Enter element a%d%d: ",i+1,j+1);scanf("%d",&a[i][j]);       }
/* Storing elements of second matrix entered by user. */
printf("Enter elements of 2nd matrix:\n");for(i=0;i<r;++i)for(j=0;j<c;++j)       {printf("Enter element a%d%d: ",i+1,j+1);scanf("%d",&b[i][j]);       }
/*Adding Two matrices */
for(i=0;i<r;++i)for(j=0;j<c;++j)           sum[i][j]=a[i][j]+b[i][j];
/* Displaying the resultant sum matrix. */
printf("\nSum of two matrix is: \n\n");for(i=0;i<r;++i)for(j=0;j<c;++j)       {printf("%d   ",sum[i][j]);if(j==c-1)printf("\n\n");       }
return 0;}

结果输出：

10、C语言矩阵转置

源代码：

#include <stdio.h>int main(){int a[10][10], trans[10][10], r, c, i, j;printf("Enter rows and column of matrix: ");scanf("%d %d", &r, &c);
/* Storing element of matrix entered by user in array a[][]. */printf("\nEnter elements of matrix:\n");for(i=0; i<r; ++i)for(j=0; j<c; ++j)    {printf("Enter elements a%d%d: ",i+1,j+1);scanf("%d",&a[i][j]);    }/* Displaying the matrix a[][] */printf("\nEntered Matrix: \n");for(i=0; i<r; ++i)for(j=0; j<c; ++j)    {printf("%d  ",a[i][j]);if(j==c-1)printf("\n\n");    }
/* Finding transpose of matrix a[][] and storing it in array trans[][]. */for(i=0; i<r; ++i)for(j=0; j<c; ++j)    {       trans[j][i]=a[i][j];    }
/* Displaying the transpose,i.e, Displaying array trans[][]. */printf("\nTranspose of Matrix:\n");for(i=0; i<c; ++i)for(j=0; j<r; ++j)    {printf("%d  ",trans[i][j]);if(j==r-1)printf("\n\n");    }return 0;}

本文系转载，前往查看

如有侵权，请联系 cloudcommunity@tencent.com 删除。

c 语言