#include <iostream>
#include <string>
#include <string.h>
#include <cstring>
#include <stdio.h>
using namespace std;

char initdigits[81];
char iterations[16][81];
int digitcount[10];
int steps;
bool flag;

void transform(int n) {
	for (int i = 0; i < 10; i++)
		digitcount[i] = 0;
	for (int i = 0; iterations[n][i] != 0; i++) {
		switch (iterations[n][i]) {
		case '0':
			digitcount[0]++;
			break;
		case '1':
			digitcount[1]++;
			break;
		case '2':
			digitcount[2]++;
			break;
		case '3':
			digitcount[3]++;
			break;
		case '4':
			digitcount[4]++;
			break;
		case '5':
			digitcount[5]++;
			break;
		case '6':
			digitcount[6]++;
			break;
		case '7':
			digitcount[7]++;
			break;
		case '8':
			digitcount[8]++;
			break;
		case '9':
			digitcount[9]++;
			break;
		}
	}
	int temp = 0;
	for (int i = 0; i < 10; i++) {
		if (digitcount[i]) {
			if (digitcount[i] >= 10) {
				iterations[n+1][temp++] = digitcount[i] / 10 + '0';
				iterations[n+1][temp++] = digitcount[i] % 10 + '0';
			}
			else {
				iterations[n+1][temp++] = digitcount[i] % 10 + '0';
			}
			iterations[n+1][temp++] = i + '0';
		}
	}
}

int finddigits(int n) {
	for (int i = n - 1; i >= 0; i--) {
		if (strcmp(iterations[i], iterations[n]) == 0)
			return i;
	}
	return -1;
}


int main() {
	memset(initdigits, 0, sizeof(initdigits));
	memset(iterations, 0, sizeof(iterations));
	while (cin >> initdigits) {
		if (strcmp(initdigits, "-1") == 0)
			break;
		flag = false;
		steps = 0;
		strcpy_s(iterations[0], initdigits);
		while (steps <= 15) {
			transform(steps);
			steps++;
			if (strcmp(iterations[steps - 1], iterations[steps]) == 0) {
				if(steps==1)
					cout << initdigits << " is self-inventorying" << endl;
				else
					cout << initdigits << " is self-inventorying after " << (steps - 1) << " steps" << endl;
				flag = true;
				break;
			}
		}
		steps = 1;
		while (steps <= 15 && flag == false) {
			if (finddigits(steps) != -1) {
				cout << initdigits << " enters an inventory loop of length " << (steps - finddigits(steps)) << endl;
				flag = true;
				break;
			}
			steps++;
		}
		if (!flag) {
			cout << initdigits << " can not be classified after 15 iterations" << endl;
		}
		memset(initdigits, 0, sizeof(initdigits));
		memset(iterations, 0, sizeof(iterations));
	}
	return 0;
}

• Re:测试数据都对，一直WA。求高人指点，谢谢 (13) witstorm 2018-01-03 15:22:17