poj 3448 Roman Expressions

poj 3448 Roman Expressions

#include <stdio.h>#include <string.h>#define N 10050#define PLUS 1#define SUB 2char *hundred[10] ={ "", "C", "CC", "CCC", "CD", "D", "DC", "DCC", "DCCC", "CM" };char *ten[10] ={ "", "X", "XX", "XXX", "XL", "L", "LX", "LXX", "LXXX", "XC" };char *one[10] ={ "", "I", "II", "III", "IV", "V", "VI", "VII", "VIII", "IX" };int reg[10];void analysis(char *cmd);int depre(char c);int roman_to_int(char *rm);void int_to_roman(int n, char *rm);void reset_reg();void substr(char *dest, char *src, int begin, int end);int main(){ char cmd[N]; reset_reg(); while (1) { scanf("%s", cmd); if (!strcmp("QUIT", cmd)) { printf("Bye"); break; } if (!strcmp("RESET", cmd)) { reset_reg(); printf("Readyn"); } else analysis(cmd); } return 0;}void analysis(char *cmd){ int i, reg_id, pbegin, result = 0, t, mode = PLUS; char result_rm[10000], str[10000], num[10000]; sscanf(cmd, "%d=%s", ®_id, str); i = -1; pbegin = 0; do {  i++; if (str[i] == '+' || str[i] == '-' || str[i] == '') { substr(num, str, pbegin, i - 1); if (num[0] >= '0' && num[0] <= '9') { sscanf(num, "%d", &t); t = reg[t]; if (t == -1) { printf("Errorn"); return; } } else  t = roman_to_int(num); if (mode == PLUS) result += t; else if (mode == SUB) result -= t; pbegin = i + 1; mode = (str[i] == '+' ? PLUS : SUB); } }while (str[i] != ''); if (result > 10000 || result < 0) { printf("Errorn"); return; } reg[reg_id] = result; int_to_roman(result, result_rm); printf("%d=%sn", reg_id, result_rm);}int roman_to_int(char *rm){ int i, len = strlen(rm), result = 0, t1, t2; if (rm[0]=='O') return 0; for (i = 0; i < len; i++) { t1 = depre(rm[i]); if (i > 0) { t2 = depre(rm[i-1]); if (t2 < t1) result -= t2; } if (i < len-1) { t2 = depre(rm[i+1]); if (t2 > t1) continue; result += t1; } } result += depre(rm[len-1]); return result;}void int_to_roman(int n, char *rm){ char result[1000]; int d, i, rest; if (!n) { strcpy(rm, "O"); return; } memset(rm, 0, sizeof(char) * 1000); memset(result, 0, sizeof(char) * 1000); rest = n; if (rest / 1000) { d = rest / 1000; for (i = 0; i < d; i++) result[i] = 'M'; result[d] = ''; rest = rest -d * 1000; } if (rest / 100) { d = rest / 100; rest = rest -d * 100; strcat(result, hundred[d]); } if (rest / 10) { d = rest / 10; rest = rest -d * 10; strcat(result, ten[d]); } if (rest) strcat(result, one[rest]); strcpy(rm, result);}int depre(char c){ switch (c) { case 'I': return 1; case 'V': return 5; case 'X': return 10; case 'L': return 50; case 'C': return 100; case 'D': return 500; case 'M': return 1000; } return -1;}void reset_reg(){ int i; for (i = 0; i < 10; i++) reg[i] = -1;}void substr(char *dest, char *src, int begin, int end){ int i, pos = 0; for (i = begin; i <= end; i++) { dest[pos] = src[i]; pos++; } dest[pos] = '';}