1 /*  2  * input: an expression seperated by a '-' or '+'; for example: a-b, a+b  3  * ouput: the answer of the input expression  4 */  5 #include 
     
        6 #include 
      
         7   8 #define MAX_N 205  9  10 char a[MAX_N], b[MAX_N], ans[MAX_N]; 11 char op; 12  13 void reverse(char *s) { 14     size_t len = strlen(s); 15     size_t i; 16  17     for (i = 0; i < (len>>1); i++) { 18         s[i] ^= s[len-i-1]; 19         s[len-i-1] ^= s[i]; 20         s[i] ^= s[len-i-1]; 21     } 22 } 23  24 void balance(char *a, char *b) { 25     size_t len_a = strlen(a); 26     size_t len_b = strlen(b); 27  28     while (len_a < len_b) { 29         a[len_a++] = '0'; 30         a[len_a] = '\0'; 31     } 32     while (len_b < len_a) { 33         b[len_b++] = '0'; 34         b[len_b] = '\0'; 35     } 36 } 37  38 void reduce(char *s) { 39     size_t len = strlen(s); 40      41     while (len > 1 && s[len-1] == '0') len--; 42     s[len] = '\0'; 43 } 44  45 void add(char *res, char *a, char *b) { 46     reverse(a); 47     reverse(b); 48     balance(a, b); 49  50     size_t n = strlen(a); 51     size_t i; 52     int c = 0, x; 53     char s[MAX_N]; 54  55     for (i = 0; i < n; i++) { 56         x = (a[i] - '0') + (b[i] - '0') + c;                 57         c = x / 10; 58         s[i] = x % 10 + '0';                 59     } 60     if (c > 0) s[i++] = c + '0'; 61     s[i] = '\0'; 62  63     reduce(a); 64     reduce(b); 65     reverse(a); 66     reverse(b); 67     reverse(s); 68  69     strcpy(res, s); 70 } 71  72 void sub(char *res, char *a, char *b) { 73     if (strlen(a) < strlen(b) || (strlen(a) == strlen(b) && strcmp(a, b) < 0)) { 74         res[0] = '-'; 75         sub(res+1, b, a); 76         return ; 77     }     78  79     reverse(a); 80     reverse(b); 81     balance(a, b); 82  83     char s[MAX_N]; 84     size_t n = strlen(a); 85     size_t i; 86  87     int c = 0, x; 88     for (i = 0; i < n; i++) { 89         x = a[i] - b[i] - c; 90         c = 0; 91         if (x < 0) { 92             x += 10; 93             c = 1;         94         }     95         s[i] = x + '0'; 96     } 97      98     s[n] = '\0'; 99     100     reduce(s);101     reduce(b);102     reverse(a);103     reverse(b);104     reverse(s);105     strcpy(res, s);106 }107 108 void input() {109     char s[MAX_N];110     scanf("%s", s);111 112     size_t len = strlen(s);113     size_t i;114     for (i = 0; i < len; i++) 115         if (s[i] != '-' && s[i] != '+') a[i] = s[i];116         else break;117     a[i] = '\0';118 119     op = s[i];120 121     strcpy(b, s+i+1);122 }123 124 void output()  {125     if (op == '-') 126         sub(ans, a, b);127     else128         add(ans, a, b);129     puts(ans);130 }131 132 int main(void) {133     int T;134     scanf("%d", &T);135     while ( T-->0) {136         input();    137         output();138     }139 140     return 0;141 }