注意数据格式，可以是整数，并且注意输出最简化浮点数。
1 #include <stdio.h> 2 #include <string.h> 3 4 #define MAXNUM 420 5 6 char a[MAXNUM], b[MAXNUM], c[MAXNUM], d[MAXNUM]; 7 int lena, lenb; 8 int posa, posb; 9 10 int addf(int bega, int begb, int *carry); 11 int addi(int enda, int endb, int carry); 12 void add(); 13 void output(int in, int fn); 14 15 int main() { 16 17 while (scanf("%s %s", a, b) != EOF) { 18 add(); 19 memset(a, 0, sizeof(a)); 20 memset(b, 0, sizeof(b)); 21 memset(c, 0, sizeof(c)); 22 memset(d, 0, sizeof(d)); 23 } 24 25 return 0; 26 } 27 28 void add() { 29 int i, carry, in, fn; 30 31 posa = posb = -1; 32 for (i=0; i<MAXNUM; ++i) { 33 if (a[i] == ' ') 34 break; 35 else if (a[i] == '.') 36 posa = i; 37 else 38 a[i] -= '0'; 39 } 40 lena = i; 41 if (posa == -1) 42 posa = lena; 43 44 for (i=0; i<MAXNUM; ++i) { 45 if (b[i] == ' ') 46 break; 47 else if (b[i] == '.') 48 posb = i; 49 else 50 b[i] -= '0'; 51 } 52 lenb = i; 53 if (posb == -1) 54 posb = lenb; 55 56 fn = addf(posa+1, posb+1, &carry); 57 in = addi(posa, posb, carry); 58 output(in, fn); 59 } 60 61 void output(int in, int fn) { 62 int i; 63 64 // printf the integer part 65 while (in>=0 && c[in]==0) 66 --in; 67 if (in < 0) 68 printf("0"); 69 else { 70 for (i=in; i>=0; --i) 71 printf("%d", c[i]); 72 } 73 74 fflush(stdout); 75 // printf the float part 76 while (fn>=0 && d[fn]==0) 77 --fn; 78 if (fn>=0) { 79 printf("."); 80 for (i=0; i<=fn; ++i) 81 printf("%d", d[i]); 82 } 83 printf(" "); 84 fflush(stdout); 85 } 86 87 int addi(int enda, int endb, int carry) { 88 int cn = 0; 89 90 while (enda || endb) { 91 c[cn] += carry; 92 if (enda) { 93 --enda; 94 c[cn] += a[enda]; 95 } 96 if (endb) { 97 --endb; 98 c[cn] += b[endb]; 99 } 100 carry = c[cn]/10; 101 c[cn] %= 10; 102 ++cn; 103 } 104 c[cn] += carry; 105 106 return cn; 107 } 108 109 int addf(int bega, int begb, int *carry) { 110 int i, len, ov = 0; 111 int flena = lena - bega; 112 int flenb = lenb - begb; 113 114 len = (flena>flenb) ? flena : flenb; 115 116 for (i=len-1; i>=0; --i) { 117 d[i] += ov; 118 if (bega+i < lena) 119 d[i] += a[bega+i]; 120 if (begb+i < lenb) 121 d[i] += b[begb+i]; 122 ov = d[i]/10; 123 d[i] %= 10; 124 } 125 126 *carry = ov; 127 128 return len; 129 }