68.md

C 程序：查找三个数字中最大的数字

原文： https://www.programiz.com/c-programming/examples/largest-number-three

在此示例中，您将学习在用户输入的三个数字中找到最大的数字。

要理解此示例，您应该了解以下 C 编程主题：

• C 编程运算符
• C if...else语句

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示例 1：使用if语句

#include <stdio.h>
int main() {
    double n1, n2, n3;
    printf("Enter three different numbers: ");
    scanf("%lf %lf %lf", &n1, &n2, &n3);

    // if n1 is greater than both n2 and n3, n1 is the largest
    if (n1 >= n2 && n1 >= n3)
        printf("%.2f is the largest number.", n1);

    // if n2 is greater than both n1 and n3, n2 is the largest
    if (n2 >= n1 && n2 >= n3)
        printf("%.2f is the largest number.", n2);

    // if n3 is greater than both n1 and n2, n3 is the largest
    if (n3 >= n1 && n3 >= n2)
        printf("%.2f is the largest number.", n3);

    return 0;
} 

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示例 2：使用if...else阶梯

#include <stdio.h>
int main() {
    double n1, n2, n3;
    printf("Enter three numbers: ");
    scanf("%lf %lf %lf", &n1, &n2, &n3);

    // if n1 is greater than both n2 and n3, n1 is the largest
    if (n1 >= n2 && n1 >= n3)
        printf("%.2lf is the largest number.", n1);

    // if n1 is greater than both n2 and n3, n1 is the largest
    else if (n2 >= n1 && n2 >= n3)
        printf("%.2lf is the largest number.", n2);

    // if both above conditions are false, m3 is the largest
    else
        printf("%.2lf is the largest number.", n3);

    return 0;
} 

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示例 3：使用嵌套if...else

#include <stdio.h>
int main() {
    double n1, n2, n3;
    printf("Enter three numbers: ");
    scanf("%lf %lf %lf", &n1, &n2, &n3);

    if (n1 >= n2) {
        if (n1 >= n3)
            printf("%.2lf is the largest number.", n1);
        else
            printf("%.2lf is the largest number.", n3);
    } else {
        if (n2 >= n3)
            printf("%.2lf is the largest number.", n2);
        else
            printf("%.2lf is the largest number.", n3);
    }

    return 0;
} 

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上面所有这些程序的输出将相同。

Enter three numbers: -4.5
3.9
5.6
5.60 is the largest number.