c语言编程实现百元发票小写转大写

具体实现如下：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

char *toUpper(char *str) {
    for (int i = 0; i < strlen(str); i++) {
        if (str[i] >= 'a' && str[i] <= 'z') {
            str[i] = str[i] - 'a' + 'A';
        }
    }
    return str;
}

void digitToUpper(char ch, char *str) {
    switch (ch) {
        case '0':
            strcat(str, "零");
            break;
        case '1':
            strcat(str, "壹");
            break;
        case '2':
            strcat(str, "贰");
            break;
        case '3':
            strcat(str, "叁");
            break;
        case '4':
            strcat(str, "肆");
            break;
        case '5':
            strcat(str, "伍");
            break;
        case '6':
            strcat(str, "陆");
            break;
        case '7':
            strcat(str, "柒");
            break;
        case '8':
            strcat(str, "捌");
            break;
        case '9':
            strcat(str, "玖");
            break;
    }
}

void unitToUpper(int index, char *str) {
    switch (index) {
        case 0:
            strcat(str, "元");
            break;
        case 1:
            strcat(str, "拾");
            break;
        case 2:
            strcat(str, "佰");
            break;
        case 3:
            strcat(str, "仟");
            break;
        case 4:
            strcat(str, "万");
            break;
        case 5:
            strcat(str, "拾");
            break;
        case 6:
            strcat(str, "佰");
            break;
        case 7:
            strcat(str, "仟");
            break;
    }
}

void convert(char *num, char *result) {
    int len = strlen(num);
    int index = 0;
    int flag = 0;
    for (int i = len - 1; i >= 0; i--) {
        if (num[i] == '0') {
            if (flag == 0 || (index % 4) == 0) {  //处理零的情况
                digitToUpper(num[i], result);
                flag = 1;
            }
        } else {
            digitToUpper(num[i], result);  //处理数字
            unitToUpper(index, result);    //处理单位
            flag = 0;
        }
        index++;
    }
    if (num[len - 1] == '0') {
        int i = strlen(result) - 2;
        for (; i >= 0; i--) {
            if (result[i] == '元')
                break;
        }
        result[i] = '\0';  //去掉结尾的“零元”
    }
    strcat(result, "整");  //加上“整”
}

int main(int argc, char const *argv[]) {
    char numStr[20];
    char result[100] = "";
    char *numUpper;

    printf("请输入金额：");
    scanf("%s", numStr);

    convert(numStr, result);
    numUpper = toUpper(result);

    printf("转换后的金额为：%s\n", numUpper);
    return 0;
}

运行截图：


此代码来自于洛谷：https://www.luogu.com.cn/record/45488627。