hdu 3925 一道复杂的简单题

题目意思简单，思路也挺简单的，可是打代码可不容易，我已经WA一下午了，至今没有AC，希望路过的大牛帮忙测测，将测试数据发给我，我将感激不尽……

/*
 * hdu3925/win.cpp
 * Created on: 2011-9-20
 * Author    : ben
 */
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
using namespace std;

const int MAX = 100000000;

int ans;
char stra[200], strb[20];
bool carry[200];
int lenb, lena;

void work();
int main() {
#ifndef ONLINE_JUDGE
    freopen("data2.in", "r", stdin);
#endif
    work();
    return 0;
}

void count(int s) {
    int ret = 0, base;
    int temp;
    if (lena - lenb - s < 9) {
        base = (int) pow(10.0, lena - lenb - s);
    } else {
        base = MAX;
    }
    int e = lenb;
    memset(carry, 0, sizeof(carry));
    if (stra[s + e - 1] != strb[e - 1]) {
        carry[e] = true;
    }
    while (e > 0) {
        e--;
        temp = (strb[e] - stra[s + e] - carry[e + 1] + 10) % 10;
        if (temp > 0) {
            if (base >= MAX) {
                return;
            }
            ret += base * temp;
            if (ret > ans) {
                return;
            }
        }
        if (stra[s + e] + carry[e + 1] > strb[e]) {
            carry[e] = true;
        }
        if (base < MAX) {
            base *= 10;
        }
    }
    if (carry[lenb]) {
        if (s + lenb == lena) {
            ret++;
        } else {
            int i = lena - s;
            if (i > lenb) {
                i--;
                ret += 10 - stra[s + i] + '0';
                base = 10;
            }
            while (i > lenb) {
                i--;
                ret += ('9' - stra[s + i]) * base;
                if (base < MAX) {
                    base *= 10;
                }
                if (ret > ans) {
                    return;
                }
            }
        }
    }
    if (ret < ans) {
        ans = ret;
    }
}

void work() {
    int T;
    scanf("%d", &T);
    for (int t = 1; t <= T; t++) {
        stra[0] = '0';
        scanf("%s %s", stra + 1, strb);
        lenb = strlen(strb);
        lena = strlen(stra);
        if (lena <= lenb) {
            int a, b;
            sscanf(stra + 1, "%d", &a);
            sscanf(strb, "%d", &b);
            ans = b - a;
            printf("Case #%d: %d\n", t, (int) ans);
            continue;
        }
        char *p = strstr(stra + 1, strb);
        if (p) {
            ans = 0;
        } else if (strcmp(strb, "0") == 0) {
            ans = 10 - stra[lena - 1] + '0';
        } else {
            ans = MAX;
            for (int i = 0; i <= lena - lenb; i++) {
                count(i);
            }
        }
        printf("Case #%d: %d\n", t, ans);
    }
}

另外，再附上一个别人过了的代码，其实思路跟我的差不太多了。不明白我的为什么还不过……

#include<cstdio>
#include<string>
#include<algorithm>
#include<cmath>
using namespace std;
char stra[200], strb[20];
int main() {
    int arr[101];
    string str1, str2;
    int T;
    scanf("%d", &T);
    for (int t = 1; t <= T; t++) {
        int a = 0, b = 0;
        scanf("%s %s", stra, strb);
        str1 = string(stra);
        str2 = string(strb);
        int lena = str1.size();
        int lenb = str2.size();
        if (strstr(stra, strb)) {
            printf("Case #%d: 0\n", t);
            continue;
        }
        int min = 1000000000;
        if (lena < lenb) {
            sscanf(stra, "%d", &a);
            sscanf(strb, "%d", &b);
            printf("Case #%d: %d\n", t, b - a);
            continue;
        } else {
            str1 = "00" + str1;
            while (str2.size() <= (unsigned int) (lena + 1)) {
                string s = str2;
                int k = str2.size() - 1, g = lena + 2;
                for (int i = lena + 1; i > lena + 1 - (int)str2.size(); i--) {
                    --g;
                    if (str2[k] - str1[i] < 0) {
                        arr[g] = (str2[k] - '0') + 10 - (str1[i] - '0');
                        str2[k - 1]--;
                    } else {
                        arr[g] = str2[k] - '0' - (str1[i] - '0');
                    }
                    k--;
                    if (k == -1) {
                        break;
                    }
                }
                while (arr[g] == 0) {
                    g++;
                }
                if (lena + 1 - g + 1 < 9) {
                    int tmin = 0;
                    for (int i = g; i <= lena + 1; i++) {
                        tmin = tmin * 10 + arr[i];
                    }
                    if (min > tmin) {
                        min = tmin;
                    }
                }
                str2 = s;
                str2 = str2 + '0';
            }
        }
        printf("Case #%d: %d\n", t, min);
    }
    return 0;
}