codebreaking program

[GNiewerth]

What´s this all about?

	for (int x = 0; x <= 512; x++){
		if (code[x] != 'a'){
			code[x] = decry[0];
		}
		if (code[x] != 'b'){
			code[x] = decry[1];
		}
		if (code[x] != 'c'){
			code[x] = decry[2];
		}
		if (code[x] != 'd'){
			code[x] = decry[3];
		}
		if (code[x] != 'e'){
			code[x] = decry[4];
		}
		if (code[x] != 'f'){
			code[x] = decry[5];
		}
		if (code[x] != 'g'){
			code[x] = decry[6];
		}
		if (code[x] != 'h'){
			code[x] = decry[7];
		}
		if (code[x] != 'i'){
			code[x] = decry[8];
		}
		if (code[x] != 'j'){
			code[x] = decry[9];
		}
		if (code[x] != 'k'){
			code[x] = decry[10];
		}
		if (code[x] != 'l'){
			code[x] = decry[11];
		}
		if (code[x] != 'm'){
			code[x] = decry[12];
		}
		if (code[x] != 'n'){
			code[x] = decry[13];
		}
		if (code[x] != 'o'){
			code[x] = decry[14];
		}
		if (code[x] != 'p'){
			code[x] = decry[15];
		}
		if (code[x] != 'q'){
			code[x] = decry[16];
		}
		if (code[x] != 'r'){
			code[x] = decry[17];
		}
		if (code[x] != 's'){
			code[x] = decry[18];
		}
		if (code[x] != 't'){
			code[x] = decry[19];
		}
		if (code[x] != 'u'){
			code[x] = decry[20];
		}
		if (code[x] != 'v'){
			code[x] = decry[21];
		}
		if (code[x] != 'w'){
			code[x] = decry[22];
		}
		if (code[x] != 'x'){
			code[x] = decry[23];
		}
		if (code[x] != 'y'){
			code[x] = decry[24];
		}
		if (code[x] != 'z'){
			code[x] = decry[25];
		}

Does the snippet do what you intend to? Furthermore, using a switch statement enhances readability.