传送门
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 <stdio.h>
6 #include <string.h>
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 else
128 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 }
