1035. Password

#include <stdio.h>int main(){int n,i,j,flag,modified=0,m[2000];char Password[2000][11];scanf("%d",&n);for (i = 0; i < 2 * n; i++) {scanf("%s", Password[i]);m[i] = 0;}for (i = 1; i < 2 * n; i += 2) {flag = 0;for (j = 0; Password[i][j] != '\0'; j++)switch (Password[i][j]) {case '1':Password[i][j] = '@'; flag = 1; break;case '0':Password[i][j] = '%'; flag = 1; break;case 'l':Password[i][j] = 'L'; flag = 1; break;case 'O':Password[i][j] = 'o'; flag = 1; break;}if (flag) {modified++;m[i] = 1;}}if (modified) {printf("%d\n", modified);for (i = 1; i < 2 * n; i += 2) if(m[i]){printf("%s ",Password[i-1]);printf("%s\n", Password[i]);}}else if (n == 1)printf("There is 1 account and no account is modified");else printf("There are %d accounts and no account is modified",n);return 0;}