解题思路：
本题乍一看上十分无聊，但又是一个 常见功能的实现，判断密码强度。对于思维锻炼和性子磨练还是有好处的  ^~^ ^~^ 

1、建议将五个 判分条件 封装成函数，来优化代码的可读性。

#include <stdio.h>

void score_judge(unsigned int score) {
    if (score >= 90) {
        printf("VERY_SECURE\n");
    } else if (score >= 80) {
        printf("SECURE\n");
    } else if (score >= 70) {
        printf("VERY_STRONG\n");
    } else if (score >= 60) {
        printf("STRONG\n");
    } else if (score >= 50) {
        printf("AVERAGE\n");
    } else if (score >= 25) {
        printf("WEAK\n");
    } else {
        printf("VERY_WEAK\n");
    }
}

unsigned int length_judge(unsigned int length) {
    if (length >= 8) {
        return 25;
    } else if (length >=5) {
        return 10;
    } else {
        return 5;
    }
}

unsigned int words_judge(unsigned int xiaoxie, unsigned int daxie) {
    if ((xiaoxie == 0) && (daxie == 0)) {
        return 0;
    } else if (((xiaoxie != 0) && (daxie == 0)) || ((xiaoxie == 0) && (daxie != 0))) {
        return 10;
    } else {
        return 20;
    }
}

unsigned int shuzi_judge(unsigned int shuzi) {
    if (shuzi >1) {
        return 20;
    } else if (shuzi == 1) {
       return 10;
    } else {
        return 0;
    }
}

unsigned int special_char_judge(unsigned int special) {
    if (special >1) {
        return 25;
    } else if (special == 1) {
       return 10;
    } else {
        return 0;
    }
}

unsigned int special_score_judge(unsigned int xiaoxie, unsigned int daxie, unsigned int shuzi, unsigned int special) {
    unsigned int sum = xiaoxie + daxie;
    if ((xiaoxie != 0) && (daxie != 0) && (shuzi != 0) && (special != 0)) {
        return 5;
    } else if ((sum != 0) && (shuzi != 0) && (special == 0)) {
        return 2;
    } else if ((sum != 0) && (shuzi != 0) && (special != 0)) {
        return 3;
    }
    return 0;
}

int main(void) {
    char str[301] = {0};
    unsigned int score = 0;
    while (fgets(str, 301, stdin)) {
        unsigned length = strlen(str) -1;
        
        score = length_judge(length);  // 1、 长度判断
        unsigned int xiaoxie = 0;
        unsigned int daxie = 0;
        unsigned int shuzi = 0;
        unsigned int special = 0;
        for (unsigned int i = 0; i <length; i++) {
            if((str[i] >= 'a') && (str[i] <= 'z')) {
                xiaoxie ++;
            } else if ((str[i] >= 'A') && (str[i] <= 'Z')) {
                daxie++;
            } else if ((str[i] >= '0') && (str[i] <= '9')) {
                shuzi++;
            } else if (((str[i] >= 0x21) && (str[i] <= 0x2F)) || ((str[i] >= 0x3A) && (str[i] <= 0x40)) || ((str[i] >= 0x5B) && (str[i] <= 0x60)) || ((str[i] >= 0x7B) && (str[i] <= 0x7E))) {
                special++;
            }
        }
        
        score += words_judge(xiaoxie, daxie); // 2 字母判断
        score += shuzi_judge(shuzi); // 3 数字判断
        score += special_char_judge(special); // 4 符号判断
        score += special_score_judge(xiaoxie, daxie, shuzi, special); // 奖励判断
        score_judge(score); // 根据评分打印
    }
    return 0;
}