题解 | 手机键盘--情况重复较多，注意次数

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

int main() {
    char str[10000];
    while (scanf("%s", str) != EOF) { // 注意 while 处理多个 case
        int n = strlen(str);
        int preIndex = -1;
        int curIndex;
        int sum = 0;
        for (int i = 0; i < n; i++) {
            if (str[i] >= 'a' && str[i] <= 'c') {
                curIndex = 1;
                sum += str[i] - 'a' + 1;
            } else if (str[i] >= 'd' && str[i] <= 'f') {
                curIndex = 2;
                sum += str[i] - 'd' + 1;
            } else if (str[i] >= 'g' && str[i] <= 'i') {
                curIndex = 3;
                sum += str[i] - 'g' + 1;
            } else if (str[i] >= 'j' && str[i] <= 'l') {
                curIndex = 4;
                sum += str[i] - 'j' + 1;
            } else if (str[i] >= 'm' && str[i] <= 'o') {
                curIndex = 5;
                sum += str[i] - 'm' + 1;
            } else if (str[i] >= 'p' && str[i] <= 's') {
                curIndex = 6;
                sum += str[i] - 'p' + 1;
            } else if (str[i] >= 't' && str[i] <= 'v') {
                curIndex = 7;
                sum += str[i] - 't' + 1;
            } else if (str[i] >= 'w' && str[i] <= 'z') {
                curIndex = 8;
                sum += str[i] - 'w' + 1;
            }

            if (preIndex == curIndex) {
                sum += 2;
            }
            preIndex = curIndex;
        }

        printf("%d\n", sum);
        sum = 0;
    }

    return 0;
}