JAM计数法

#include<iostream>
using namespace std;
const int N = 1000;
int main() {
	int s, t, w, flag = 0;
	char a[N];
	int j, i, num = 0;

	scanf("%d%d%d", &s, &t, &w);//s->min order of alphabet,t is max;w is the bits of num;1??s<T??26, 2??w??t-s ??
	scanf("%s", a);
	for (;num < 5;num++) {
		//TODO
		for (i = w - 1; i >= 0; i--) {
			//TODO from last bit find that add able num
			flag = 0;
			if ((a[i] + 1 >= 96 + s) && (a[i] + 1 <= 96 + t)) {
				//ascii a->97
				if (i != w - 1) {
					if (a[i] + 1 < a[i + 1]) {
						a[i] += 1;
						flag = 1;
					}
				}
			} else {//last bit just need add 1
				a[i] += 1;
				flag = 1;
			}


			for (j = i + 1; j <= w - 1 && flag == 1; j++) {
				while ((a[j] - 1 >= 96 + s) && (a[j] - 1 <= 96 + t)) {
					if (a[j] - 1 > a[j - 1]) {
						a[j] = a[j] - 1;
					} else {
						break;
					}
				}

			}
			if (flag == 1) {
				break;
			}

		}
		printf("%s\n", a);
		
	}
	return 0;
}
``